Yeah, this is pretty common. After you remove keywords from a businesses Google Business Profile title, they are likely to just add them back. And this is because Google rarely does anything about adding keywords.
It is against their terms of service. You could get suspended, but it's very rare, which is why we actually encourage our clients to do it subtly. We wouldn't be this egregious about it, but what we do for our clients competitors is we just go in once a month and remove them again.
So the more aggressive competitors might get them back in a day or two. Most of them will give up after a while, though, as they're not told that someone else removed the keywords. They just get an email from Google saying the keywords have been removed, and that's usually enough to scare the competitors after a few emails.