Messenger App Problem

I have two machines with the latest version of Windows 10 on them.
On one of them, the Messenger app suddenly started malfunctioning.
It runs but for an instant (I recorded it on video!) it throws up a message saying I'm using a browser which isn't supported by Facebook! This is obviously nonsense. It then tries to load what appears to be the mobile site, but does not succeed and keeps on looping round and round trying to load.
The same Messenger app on the other machine is still fine.
Anyone any idea why this might be happening?
A search has produced no results.
Thanks, Dave.

I haven't experienced this, so I'm not sure if it will work, but try the following:
Make sure the Messenger app on the problem computer is up to date.
Make sure the date and time settings on the problem computer are correct. Incorrect date and time settings can sometimes cause problems with authentication in online services.
Clear the Messenger cache and cookies. Cached data can cause conflicts, and clearing it can solve the looping problem.
Some sites also say that some older or less common devices may not be compatible with the latest version of Facebook or its features. In such cases, Facebook may display an "unsupported" message.

Thanks for that, but sorry I should have updated this myself.
I subsequently discovered that the faulty Messenger app I had installed was not the 'official' one published by Meta.
The one on my other machine, which works, is.
The faulty third party app is obviously just out of date, and there is no newer version.
I can't now install the Meta Messenger app on the second machine, as it appears to now only be available in 64 bit.
The second machine is running 32-bit Windows 10, so I guess there's nothing I can do.
I've searched and searched and I cannot find any 32 bit version of the Meta Messenger app.