'Internal Server Error' when setting up MFA/2FA

when I initially setup my instance I made separate admin and user accounts for myself. the admin account has 2FA setup and it works correctly.

now, after some additional config, I try to go and setup my non-admin account with token-based 2FA and get the error message above

I also made a new test account with throwaway email. logged in successfully but got the same error when attempting to enable 2FA

any assistance would be appreciated, thank you <3