[4.24] After upgrade, creating encrypted patch fails with assertion

(This is a repost, my previous post a few days ago seemed to be swallowed someohow by the system)

After upgrading from 4.22 to 4.24, we face an issue when creating a patch, with encryption. It always fails with an assertion about the key.

What i did sofar:
Creating a clean 4.24 full release, and build a patch on top of that
Changing encryption keys and signature keys
Sofar nothing has helped, and I’m struggling to understand what is wrong.
Can’t upload it as attachment for some reason, so here is an excerpt from the log:

Project.RunUnrealPakInParallel: Executing 1 UnrealPak command...
Project.RunUnrealPakInParallel: Waiting for child processes to complete (1/1)
Project.RunUnrealPakInParallel: Output from: S:\Git\ProjContDev\ProjCont.uproject S:\Git\ProjContDev\Saved\StagedBuilds\WindowsNoEditor\ProjCont\Content\Paks\ProjCont-WindowsNoEditor_0_P.pak -create="C:\Users\\AppData\Roaming\Unreal Engine\AutomationTool\Logs\S+Unreal+UE_4.24\PakList_ProjCont-WindowsNoEditor_0_P.txt" -cryptokeys=S:\Git\ProjContDev\Saved\Cooked\WindowsNoEditor\ProjCont\Metadata\Crypto.json -order=S:\Git\ProjContDev\Build\WindowsNoEditor\FileOpenOrder\CookerOpenOrder.log -generatepatch=S:\Git\ProjContDev\Releases\200\WindowsNoEditor\ProjCont-WindowsNoEditor*.pak -tempfiles=S:\Unreal\UE_4.24\TempFilesProjCont-WindowsNoEditor_0_P -encryptindex -sign -patchpaddingalign=2048 -compressionformats=  -multiprocess -abslog="C:\Users\\AppData\Roaming\Unreal Engine\AutomationTool\Logs\S+Unreal+UE_4.24\UnrealPak-ProjCont-WindowsNoEditor_0_P-2020.05.05-15.01.10.txt"
Project.RunUnrealPakInParallel:   LogPakFile: Display: Parsing crypto keys from a crypto key cache file
Project.RunUnrealPakInParallel:   LogCompression: Display: FCompression::GetCompressionFormat - Unable to find a module or plugin for compression format -multiprocess
Project.RunUnrealPakInParallel:   LogPakFile: Display: Loading response file C:\Users\\AppData\Roaming\Unreal Engine\AutomationTool\Logs\S+Unreal+UE_4.24\PakList_ProjCont-WindowsNoEditor_0_P.txt
Project.RunUnrealPakInParallel:   LogPakFile: Display: Added 10412 entries to add to pak file.
Project.RunUnrealPakInParallel:   LogPakFile: Display: Loading pak order file S:\Git\ProjContDev\Build\WindowsNoEditor\FileOpenOrder\CookerOpenOrder.log...
Project.RunUnrealPakInParallel:   LogPakFile: Display: Finished loading pak order file S:\Git\ProjContDev\Build\WindowsNoEditor\FileOpenOrder\CookerOpenOrder.log.
Project.RunUnrealPakInParallel:   LogPakFile: Display: Generating patch from S:\Git\ProjContDev\Releases\200\WindowsNoEditor\ProjCont-WindowsNoEditor*.pak.
Project.RunUnrealPakInParallel:   LogWindows: Error: === Critical error: ===
Project.RunUnrealPakInParallel:   LogWindows: Error:
Project.RunUnrealPakInParallel:   LogWindows: Error: Assertion failed: Key [File:D:/Build/++UE4/Sync/Engine/Source/Developer/PakFileUtilities/Private/PakFileUtilities.cpp] [Line: 1424]
Project.RunUnrealPakInParallel:   LogWindows: Error:
Project.RunUnrealPakInParallel:   LogWindows: Error:
Project.RunUnrealPakInParallel:   LogWindows: Error:
Project.RunUnrealPakInParallel:   LogWindows: Error:
Project.RunUnrealPakInParallel: UnrealPak terminated with exit code 3
Log.WriteException: ==============================================================================
Log.WriteException: ERROR: UnrealPak failed
Log.WriteException:        (see C:\Users\\AppData\Roaming\Unreal Engine\AutomationTool\Logs\S+Unreal+UE_4.24\Log.txt for full exception trace)
Log.WriteException: 
Log.WriteException: AutomationException: UnrealPak failed
Log.WriteException:    bei Project.RunUnrealPakInParallel(List`1 Commands, List`1 LogNames, String AdditionalCompressionOptionsOnCommandLine) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\CopyBuildToStagingDirectory.Automation.cs:Zeile 2321.
Log.WriteException:    bei Project.CreatePaks(ProjectParams Params, DeploymentContext SC, List`1 PakParamsList, CryptoSettings CryptoSettings, FileReference CryptoKeysCacheFilename) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\CopyBuildToStagingDirectory.Automation.cs:Zeile 2126.
Log.WriteException:    bei Project.CreatePakUsingStagingManifest(ProjectParams Params, DeploymentContext SC) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\CopyBuildToStagingDirectory.Automation.cs:Zeile 1671.
Log.WriteException:    bei Project.ApplyStagingManifest(ProjectParams Params, DeploymentContext SC) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\CopyBuildToStagingDirectory.Automation.cs:Zeile 2916.
Log.WriteException:    bei Project.CopyBuildToStagingDirectory(ProjectParams Params) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\CopyBuildToStagingDirectory.Automation.cs:Zeile 3450.
Log.WriteException:    bei BuildCookRun.DoBuildCookRun(ProjectParams Params) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\BuildCookRun.Automation.cs:Zeile 209.
Log.WriteException:    bei BuildCookRun.ExecuteBuild() in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Scripts\BuildCookRun.Automation.cs:Zeile 39.
Log.WriteException:    bei AutomationTool.BuildCommand.Execute() in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\BuildCommand.cs:Zeile 263.
Log.WriteException:    bei AutomationTool.Automation.Execute(List`1 CommandsToExecute, Dictionary`2 Commands) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\Automation.cs:Zeile 538.
Log.WriteException:    bei AutomationTool.Automation.Process(String[] Arguments, StartupTraceListener StartupListener) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\Automation.cs:Zeile 508.
Log.WriteException:    bei AutomationTool.Program.MainProc(String[] Arguments, StartupTraceListener StartupListener) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Program.cs:Zeile 176.
Log.WriteException:    bei AutomationTool.Program.<>c__DisplayClass1_0.b__2() in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Program.cs:Zeile 88.
Log.WriteException:    bei AutomationTool.InternalUtils.RunSingleInstance(Func`1 Main) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\AutomationUtils\Utils.cs:Zeile 731.
Log.WriteException:    bei AutomationTool.Program.Main(String[] Arguments) in D:\Build\++UE4\Sync\Engine\Saved\CsTools\Engine\Source\Programs\AutomationTool\Program.cs:Zeile 88.
Log.WriteException: ==============================================================================
Program.Main: AutomationTool exiting with ExitCode=1 (Error_Unknown)