403 when creating new issues

when submitting new issues, gitlab is returning 403 errors

gitlab version: 12.10.1-ee (695c29abcf7)

we are using gitlab starter edition, self hosted

the issue happens when there’s certain input it seems, i had a few tasks in the issue description.

i was able to go around this by entering an empty description first then editing the issue, that seems to work, so only the issue create API is affected