I've got a problem with my facebook access and need some advice

on the iPad I use Chrome and facebook has suddenly changed to m.facebook.com (mobile facebook?) for no reason and when I try to open the desktop site facebook.com it just reverts to m.facebook.com.... this is very frustrating

Does anyone know how I can change it back and get the proper facebook - I don't like m.facebook.com at all, as it's not that user friendly

and what's more when I click on messenger icon it brings up a new window and asks for e-mail address and password - but the problem is I do not know the password, wife & I have never needed to use it since we reset it a couple of years ago... I used to click on messenger and it would just open up inside the FB page, but it doesn't do that now

Wife has the FB and messenger on her iPhone 6 and they work fine, same on the MacBook on Chrome it all works fine, but on the iPad it's changed - for the worse

I've also just got chrome installed on my work PC and FB wants a password for me to access it

if I click on forgotten password - will that just send me what my password actually is, or will it ask me to reset it?

I want to avoid resetting the password if at all possible, otherwise that will interfere with FB / Messenger on wifes phone and on the MacBook

and before you ask - yes wife & I share the FB page (although it is in my name)

any advice would be helpful