Well, with an increasing number of validators, the network becomes significantly weaker and more unstable. Today, just 5 minutes before validation, my node going to be unsynced and offline with zero blocks remaining. there was no chance of passing the validation with him.
Now it's suspended, what to do with them? Can I withdraw the locked balance from the stake, or I can only to delete everything and start over?
No need to do anything. Just validate on next validation and you are back in the game. This was the limit of the network but I would like to analyze your node log file to see what caused the problem, so I can give you some advices on how to maybe setup things better or what to consider.
Consider this as vacation as you don't need to make flips for next validation

Also, next validation should be easier on the nodes and network, since now network had separated to 4 shards! My node is in shard 1.
Please PM me if you want me to troubleshoot your validation problem.
We (mostly Hugo

) are solving these validation problems over on Github discussion
Desktop App:
https://github.com/idena-network/idena-go/discussions/799Web App:
https://github.com/idena-network/idena-web/discussions/123