1) Thats ok, just wait some time. The status for os updates is refresehd only a few times a day as we would might overload the repository servers of the distributions otherwise.
2) No limits were changed by the update. At least of you havent edited any of the ispconfig apache config files manually. Take a look into the error.log of the website, you fidn the reason for the problem there.
A likely issue might be this one, but thats not configured by ispconfig: