Ubuntu Core 16 crashes when NC snap updates

Dear Community,

I have been experiencing an issue for some time that I wonder if any other user has the same issue.

I have an Ubuntu Core 16 server with NC installed via snap. Every time it upgrades itself, it freezes the server. It cannot be reached via SSH or https. The only way to make it work is to disconnect the power plug and reconnect to force restarting.

Any idea why is doing that? And how to prevent it?