Hello,
(Edit: Both issues happen in an unpackaged Game, so it’s in-engine. I don’t know if they will happen in packaged. I don’t want to package yet till these bugs are fixed)
I am currently finishing up my UE5.6 multiplayer prototype with a 3x streaming level setup (and a parent persistent level). I don’t think the multiplayer part matters here as that is handled by the GMC Plugin but also these 2 issues happen in all cases (standalone, listen server, etc). So here are the 2 issues I’ve got and would be really thankful for any assistance! 
1 - This one was happening even before implementing UDS (ultra dynamic sky). Ive got a three streaming level setup with teleport in between. Second level doesnt need outside-lighting so works fine because its a dungeon, third level though, right after teleporting in it, it seems to “destroy the skylight”. Ive set my lighting/UDS to be part of the parent level (the persistent one). The teleport is just a “set actor location”. You can see the destruction of skylight in the images below.
2- I have a landscape and then I realized that the NPCs are walking weirdly only in some thin strips of land. And then I checked that navigation seems to have some holes. I try to smooth the landscape or readjust the bit, it does fix the issue but not in every place (look image).
