windows built it backup is actually ok, you can specify which folders are backed up and how often
i use nas, just an old computer running linux in my laundry room with a bunch of drives that i save everything to, and backup everything monthly to a drive i keep in my drawer and a second drive i keep in my locker at work
easiest is probably to get an external drive and copy everhing to it periodically, keeping it unplugged so youre safe from virus, accidental deletion, power supply failing and frying it, lightning things like that
something similar happened to me too, account that didnt have 2fa enabled at all suddenly asking for confirmation on a device i just wiped
it sorted itself after a couple of hours, maybe a bug