Using a Proxy outlook address, but still got "too many times user name or password".

Hi all

For months I was getting the dreaded "too many times user name or password" and a check of attempt "sign ins" showed numerous attempts to sign in from IP addresses all over the world.

In other discussions and internet search it has been suggested 

A) Create a Proxy address only known to me  (done)

B) Make this new Proxy address the only way to sign into Hotmail Microsoft (done)

C) Check to see if the original address is no longer recognized as a valid address, so that no attempt to sign in be even be attempted (done)

Yesterday morning in my first attempt (previous successful attempts were during the day before) to sign in I got the "too many times user name or password" to an address nobody else knows exists?  I tried several times yesterday to all receiving the dreaded "too many times etc"  

Obviously I have been successful to sign into Hotmail (and this community) today, though I don't know if it because of time passed and/or clearing of cookies and internet data?  

So my primary Questions 

A) How could I possibly be locked out to a Address no one else on the planet, except outlook knows about?

B) If there was something my PC could have done to inadvertently trigger the "too many times etc" error by mistake?

I am running the current up to date versions of Windows 11 and Norton 360.