Every source I can find online says that while you need to be on the mobile or desktop website to disable an account, you can enable an account using either the app or the website. More over, try as I might I can not find a single source saying that logging in via mobile can not reactivate an account.
I'm sorry but I'm going to have to doubt that while you are able to disable an account only via mobile and desktop website, and are able to enable an account via desktop website and app, you can't reactivate it via mobile website, that no one on the entire Internet talks about that fact, and that when you do try to log in via mobile website you get a banned screen as opposed to an "account not found" message or something actually related to the fact he was the one who disabled the account.