I suggest removing ram sticks, blowing into the socket, brushing the ram contacts to remove anything that could stop the connection between ram and socket and then reinserting it (firmly, with proper force) and then seeing if it helps. After inserting the ram sticks it's always good to push on both sides and in the middle, because sometimes it actually does push them 1-3mm down which secures the connection which seemed to be completed before.
If it does not you might have to boot ram testing app from a pendrive.
You might also try the screenshot one built-in windows tool, but I'd say it's kinda poo water. But if it actually does detect problems then your RAM is physically damaged (or there's still some gunk or the sockets are damaged)