Steps to Reproduce the Bug

1. Open a creative 1.21 game with JEI installed
2. try to search for something in the creative menu (not the JEI menu), eg cobblestone

Expected Behavior

Should show the results for what was input

Actual Behavior

In the newest version nothing happens, in the second newest it shows unusual results (for example "water" shows sea grass and non solid alive coral blocks)

Mod Pack URL (Optional)

No response

Mod Pack Version (Optional)

No response

Extra Notes (Optional)

No response

latest.log

https://gist.github.com/Copper-Furred-Fox/f891630c346242c88d6b49008084a959

Thanks for the report!
I am not able to reproduce this issue with only JEI.
JEI does not impact the creative menu or any vanilla code in general.

Your logs show other mods are installed, like modernfix.
Please try removing mods to see which one is causing the problem.