Universal Credit Mamas

Hi all, I need a bit of advice.

I'm on UC and just over a month ago I added my partner onto my claim as we decided to move back in together. Problem is we've now decided it was a bad idea for us (for many personal reasons) and calling it quits especially on the living situation. I need to take him back off my claim but I'm worried I'll get sanctioned incase they think I'm being dodgy. It's causing me a lot of anxiety. I was only trying to be honest in the first place and now just full of panic. Has anyone else been in the same position?

EDIT:

If I end up getting monitored on my bank account activity I'm worried they'll see that I'll still be getting sent money from my ex because we have children together and some of his bills are in my name (he couldn't get contracts in his due to bad credit scores).