blackjack table min went from $5 to $25 right after i joined with bonus balance

I was playing blackjack online last night, trying to clear a bonus, table was steady at a $5 minimum which was exactly what I needed. Ten minutes in, right after I win a hand, the table minimum jumps to $25 out of nowhere. I double checked the lobby and all the other tables switched up too, so it wasn’t just some weird glitch on one table. Super frustrating since $25 a hand is not my pace for bonus play at all.

Is this something casinos can just do whenever? I always thought they’d lock the min when a session starts, at least until a dealer change or something. It feels like they’re targeting bonus grinders or people trying to run a strategy. I ended up cashing out most of the bonus because I didn’t want to eat variance at those stakes. Anybody else have this happen or is this just the new normal online?