Thank the good Lord! I finally fixed it.
When following one of the tutorials, I was told to add this line:
DynamicallyLoadedModuleNames.Add("OnlineSubsystemSteam");
Just commenting that line out solved the issue! Note for those who may stumble across this:
If you are in UE4.26+, don’t bother doing anything crazy, don’t download the steamworks sdk. Literally all you need to do is enable the steam online subsystem plugin, use the appropriate blueprints nodes, and add this to your defaultengine.ini file:
[/Script/Engine.GameEngine]
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="OnlineSubsystemSteam.SteamNetDriver",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")
[OnlineSubsystem]
DefaultPlatformService=Steam
[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=YOUR_APP_ID
bRelaunchInSteam=false
Achievement_0_Id="YOUR_STEAM_ACH_NAME1"
Achievement_1_Id="YOUR_STEAM_ACH_NAME2"
Achievement_2_Id="YOUR_STEAM_ACH_NAME3"
[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="OnlineSubsystemSteam.SteamNetConnection"