This was actually a bug caused by the fact you cannot run multiple JCEF instances using the same cache folder.
It will be fixed with v0.3.0
https://github.com/CCBlueX/LiquidBounce/commit/0ea8751899d738cbb16c41d2b9c62146453e9132
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1zun4 committed to CCBlueX/LiquidBounce
fix: unable to run multiple MCEF instances (#2803)
Depends if you used the LiquidLauncher.
If you have used the LiquidLauncher, uninstall the launcher application and delete
%appdata%/CCBlueX/LiquidLauncher
After this all data will be gone and lost.
If you used the Minecraft launcher, all you need to do is clean your .minecraft folder of any remnants of LiquidBounce.