Spamming or clicking opening "Inventory Key" turns your character into creative mode forever and the only way to go back from survival is to edit the player save file.

Can you please state your mc version and mod version? Are you talking about the forge or the fabric version?

Ive had a similar problem im on 1.19.2 for version and using forge ive been stuck in creative. Ive resorted to save editing to fix it

Please try out the v3.0.2-beta version for 1.21 and lmk if you still have the same issue.

Please re-open the issue if it still persists for you with the version mentioned above.