One of several Yahoo emails not working

I collected my MacBook Air from the Apple Store yesterday after they performed a fresh install (for a separate issue), however, one of my 5 Yahoo email address now says "offline", but yet the other 4 Yahoo addresses are fine.

In Apple Mail (OSX 12.3.1), there isn't any option to update the password or verify the account. I shouldn't have to because nothing has actually changed (I just wanted to walk myself through it as part of the procedure when checking everything). The account works fine on my iPad Pro and iPhone, just not in the desktop Apple Mail app.

Also, when I try to send a test email, I receive a dialogue box asking to choose another outgoing server (that's because it says 'offline'). Upon opening the Connection Doctor, it shows green lights for all of my private domain name email addresses and also 4 Yahoo email addresses, but the failed address shows two red lights ("could not connect to this IMAP server"), but yet the other 4 are fine.

Everything worked great before I took the machine back to Apple Store last Friday, but after the fresh install this particular email address is now not working. My other private domain name email addresses also work fine, just not 1 of the 5 Yahoo addresses.

I have 12 email address in total. So, why do 11 email addresses work fine, but one doesn't? Again, they all work fine on my iPad Pro and iPhone. Weird.

Yahoo does not offer help unless you pay £5 or something like that.

So, does anyone have any advice?

Thanks : )