Aastra phone showing no service after applying config

For some reason today when I made changes to my server setting up a queue with Freepbx version 4.211.64-10 and Asterisk when I applied the config, all the phones after a little while showed no service and were not able to call out. This happend multiple times today when I applied the config. They did I guess reregister after a couple of minutes. They are all Aastra phones 6731,6735, and 6739. Also, for some reason it probably takes 2-3 minutes for it to apply the config. We do have around 320 extensions and with that many extensions, is this amount of time a normal amount to apply the config?

I have found out that the phones show no service right after it finishes applying the config. Then after about a minute they work again.

This is because they are dropping registration. Asterisk is probably restarting. Could be normal depending on your config