packetfixer-forge-1.4.5-1.19-to-1.20.1
Minecraft 1.20.1 forge 47.3.0

Comes and goes with RegionsUnexploredForge-0.5.6+1.20.1 and some other mods

Server_Debug: https://mclo.gs/gOnzaDl
Server_Latest: https://mclo.gs/HnkBAbg

Minecraft_Debug: https://mclo.gs/H2EH5UZ

Modlist: https://mclo.gs/QSchxco

@Wundcreme Try this version:
packetfixer-forge-2.0.0-1.19-to-1.20.1.zip

It works! Thank you very much!