FB Messenger Is Disabled In Mobile Browser

Starting 6th of December last year, Meta has implemented end-to-end encryption on messenger by default.

The extra layer of security provided by end-to-end encryption means that the content of your messages and calls with friends and family are protected from the moment they leave your device to the moment they reach the receiver’s device. This means that nobody, including Meta, can see what’s sent or said, unless you choose to report a message to us.
– Meta Platforms

However, starting middle of March most Facebook users have trouble accessing their messages via browser. Not to mention most users were unfamiliar with having a passcode for their messenger, not knowing that was their encryption key.

Due to users unable to access their messenger through the use of mobile browsers. This also removes the functionality of chatting your facebook friends through a free data version of facebook. Although, some user reports they are able to use free data with the messenger app. Some users would prefer using it via the browser.