LightSail instance crashes once per month and I don't know why

I have a lightsail instance

16 GB RAM, 4 vCPUs, 320 GB SSD

Windows Server 2019

Sydney, Zone A (ap-southeast-2a)

I'm running on it about 4 node.js webservices and IIS and a .net server, nothing too load demanding. Almost like clockwork once per month or so then entire server becomes unresponsive, I can't find anything useful in the event logs. I have to do a reboot from the console, then usually mongo or sql express don't restart afterward and I need to manually restart them.

Very frustrating and leaves my services down randomly.
Plenty of disk space, no system error logs. Anyone seen anything similar?