Reddit runs an experiment on its mobile site currently that prevents logins if a mobile web browser is used.
Some Reddit users have noticed that they can't sign-in to their accounts anymore on mobile, as the option to do so has been removed for them. Reddit has made it difficult in the past for users to access the site on mobile in browsers. The company's main intention is to get users to use the official Reddit application instead.
I checked out the official reddit app just out of curiosity. What a shit show. It felt like half the posts were ads or "recommended" posts. Spent a whole 5 minutes before deleting. Relay or nothing.