why my lightsail instance was stopped without any notice?

I setup a wordpress site, I just realise that my websites was shut down, at first I thought it was the domain that had expired but not the domain is fine then checked on semrush and notice I lost all of my traffic

why my instance was stop without any notice ?

I'm only using 4GB still have 15GB, just why stopped my instance?

so frustrating, I've been charged for nothing

is there anything that I can do to avoid this situation?