Somewhere around 6-8 months ago, I found missing & corrupt files on my Microsoft OneDrive account, at work. The folders where I noticed the problems weren't business-critical, luckily. The next day, things seemed to be back to how I expected them, so I don't know if I just happened to check on them while things were somehow in flux, or if the problem was detected and the files restored from backup. I'm hoping everything was recovered, though I don't have any way to be certain.
Needless to say, it definitely shook my confidence. OneDrive is the only place they provide for us to keep our normal files, like documents, spreadsheets, etc. We're not allowed to back them up anywhere else! Only if it's something like source code, could we put it in a Github Enterprise repository.
BTW, I also somewhat recently discovered some 15-year old emails had gotten corrputed, in an old Hotmail account. Hotmail is owned by Microsoft and has now been transitioned into their Office 365 product.