I've used them for a long time too for some of my sports betting but I do bet occasionally these days but as for checking, I don't see any change to my account. Have you asked the support why it has happened to you?
Maybe you could contest that to them if you want to revert your betting limit but if not, at least they have to let you know what has happened and why they have to reduce it.
Hopefully, a rep would reply here.
Haven't tried bitsler myself but based upon the statements of my friend who was a member of bitsler, the experience wasn't much good and nothing was special which can differentiate this from other casinos. Not being judgemental but the user experience shared on this forum and on this post also supports the stance of my friend.
There is a difference between being a bad casino and being not a great casino. I understand not finding this casino one of the best, that is understandable, but that doesn't mean that this one is a bad one neither. It just means that we are talking about a place that doesn't give back to gamblers as much as some other places do.
Gambling in the crypto world grew insanely high, which means you would be getting huge amounts back, and casinos are getting bigger so their profit margin could grow smaller. But this place hasn't grown that much, which means it is not getting that much attention anymore, and that could be what your friend was talking about.