It seems that the staff of the server have fixed the water glitch that would constantly happen and have replaced it with a glitch where you can't get in boats or place them on land like you used to be able to. On my yt which is iamawesome750 D.J. I have a stream I did where the glitch happened almost every time where you couldn't put it down or couldn't get into the boat in the water
Checked out your stream and the boats did seem to be causing a problem when trying to get into them. What you should do is clip the parts where the glitch happens (or find the timestamps for the stream) and then make a bug report at https://mccentral.org/community/forums/bugs/. An Admin/Owner will reply to your report ASAP, and it's the quickest way to get bugs like this fixed. I personally prefer this to the water glitch, as it happens to me fairly inconsistently (sometimes I can get in a boat, sometimes I can't for a few tries) unlike the water glitch which was a consistent thing.
I've also noticed that boats have become way more glitchy with the addition of the new anticheat, although I find that if you just spam right-click all over the ground it doesn't take that long and the boat actually places. It's pretty annoying but placing boats is still possible and realistically it's not the biggest issue right now, I do get the frustration though and hopefully, it'll be fixed soon
