OATs are not calculated

I complete quests, but I don’t get OATs. Once I logged into my account I had 139 OATs in my account, I was surprised because I didn’t complete many quests. A day later I went in and there were 4 OATs in the account, it was more realistic. But now I have 0 OATs in general, who knows why my OATs disappeared? Have any of you had similar experiences?