2 years is already a long time, don't know what i would have done. Try to figure out who / why even if its a bot there must be a reason.

Try to figure out what is wrong with your posts, to short/ to much copy and paste / generated by ai / offensive languages.

Maybe it can help if you set rewards to 100% HP in stead of 100% to a beneficiary or reward.app etc.

You might have tried all the above, just the things that comes to my mind.