Damn, That’s a lot of groups for a single account I’m surprised that the account is not suspended yet.
I can’t really suggest to join more groups as I’m afraid that will get you block. However, Let’s see if someone who can share their thoughts about this.
If you’re absolutely sure you’re not going to use this niche again I’d say you unjoin them and join the new ones. There is a certain point where fb will tell you that you can’t join any more groups, you might reach that if you keep those.
I will have to disagree with that Johnny as I had a bad experience while unjoining and joining after with a day or two ( The ban hammer was waiting for me ) even that the accounts were 1 - 3 years old. so I suggest maybe sending those groups to the ignore list instead and just start joining the new groups you are targeting.
If for some reason you weren’t allowed to join more groups with that account, let the account rest for 1 week after the unjoin before you start joining again.