I have a couple servers that have been online for ages until today, turned them off to do game updates, game tracker won’t update the status from offline to online, they currently have players on them and I can also see them in the game server browser. I also cannot seem to add any servers ... any ideas?

See: GameTracker unable to query Arma 3 servers etc.

The links included by 'dwarden' are worth reading.

I have 2 servers with status offline, and 3 others with the status online, same IP address for all servers ..

There appears to be a pattern there...
The three scanned servers are KF2, the others are not.
It is the game patches / updates from Steam that are the likely cause of the problem - settings which may help are suggested in one of the links in the Forum post I linked to above.

I have been assured that GT developers are working to bring our scanners up to date to manage these changes, but no timescale has yet been provided.