Information

• Server version:
  3242-Spigot-6c1c1b2-d3cc412 (MC: 1.17.1)
• Full output of /mv version -p:
  https://j.mp/3kEcbTy
• Server log:
  https://gist.github.com/RealHenning/72479a11ba9e319d15334f0d6f69473a

Help request

Problem

When I join my newly setup server I see som weird symbols and letters in the lower right corner of the screen. The letters are upside down and I believe that there's a hex digit among them.
What I have tried

I tried removing plugins from my server one by one. When I reached Multiverse-Core the symbols disappeared.
Screenshots

Test with only mv installed, and ensure you are not using a modded client.

Thanks for the tip. I thought I had tried every possible constelation, but I just retried and figured out that the problem is somehow related to InTheWilds special resource pack combined with changing worlds with MV.