Hopefully you have created that ticket and they’ll take a look and see if it can be resolved.
Unofficially from me (just another user who helps out here, not employed by Brave):
Honestly, based on timing and all, my assumption is the system had flagged/suspended your account for unusual activity. Back around the time you’re speaking of is when they had a lot of people flagged due to changes in antifraud system, as you can see at PSA: Current Rewards Issues (June 2023) *UPDATED* and then PSA: Flagged accounts issue (August 2023 update)
The only challenge here is they essentially removed the flags from all accounts at that time. Anyone still flagged would likely be permanently flagged/suspended. This is what you’ll likely be told, that it’s flagged and won’t be reinstated. But that’s just a wild guess based on everything I mentioned.
Negatives said, I’ll be hoping you have better luck and things get resolved for you.