Hi
@cammckendry
This is something that needs to be investigated, it's difficult to know why the go down just off the bat.
Some recommendations on things to check:
1) See whether the instance is actually still up, but your public IP has changed. Solution: set your network settings in the management console to dynamic so the IP will be updated
2) Check whether the services are still running. If they stop running it will be possible to see logs on the machine to learn why
3) Check whether you have duplicate instances, or if you setup something like automatic backup restores or failover
4) Check whether it is something related to your Lightsail account, shutting down the instances entirely or something related to the OS
5) If you install any 3rd party tools on those machines, ensure they are not the cause in any way that can stop the machines
The latest update came out yesterday, so I would not say that it is necessarily related, you mentioned the issues were noticed since Monday
