Realm keeps disconnecting everyone on the server after someone break a block or open a chest

Just like the summary says the server already had lag in it but now it’s alot worse that it crashes and disconnects all the players after seconds of someone doing something.

we didn’t use any commands block or anything like it we have only had the realm for less than a month 20 days to be exact, the disconnecting started yesterday at 11pm for no reason we have only had 1 player in the server at the time.