I had a very similar experience. I had a reddit account from before they required email addresses. It got flagged as "suspicious", it forced me to reset the password in order to continue, and the password reset required me to provide an email address, which I refused to do. I asked an AI agent what might have caused the flag. At the moment my account got flagged, I was arguing on reddit with some pro-China people, and I was posting links to the genocide of the Uyghurs. The agent told me that hackers probably made multiple failed attempts to log in to my account and this triggered the flag. Sounds like something similar could have been done to you by people who opposed your political views.