Problems with using multiple email addresses

Possibly a ‘new’ problem with iphone-appleid- and xfinity mobile- involving passwords and appleid email. cliffs note version follows
A) two years ago I got an SE iphone via comcast- xfinity- and used a email adress not involving my name- deliberately as I had have no plans to use it for not much more than out of retirement complex instead of my comcast " landline" and some photos.
B) so I used my name gmail for my Comcast TV and phone and internet account, and a non name gmail for my mobile account. . Got phone delivered with simcard to install.Worked well until about a month ago.
C) then mobile number became erratic ’ not avail ’ and depending on cellular on with or without my separate wi fi
D) So checking things as best I can ( using apples since 1980’s and apple II ) i elected to match with esim per instructions.
E) Blooey- phone only works with “SOS” and taking pics and sending via Airdrop,etc " calling out or calling to my landline no go.
F) Spent about an hour online with my mac mini and chat assist. In process landlne( voip) went dead- finally started working again. assist chat dissappeared-
G) phone now wants a password for a different apple id than my activate id. Seems to be my comcast email- which AFIK never used for apple id.
H) problem SEEMS to be result of Comcast deciding to meld my tv-landlne-internet account email with my name with the Mobile account using my NON personal name and thereby assuming/changing my access ID email as if it was an apple ID. ???
J) of course this happened at the personal most inopportune time whenI really needed to use iphone and over the 4th weekend.
K) It will be at least a week before I can travel to nearby woodinville and have a heart to heart chat to counter with a not too subtle message to FIXIT

Now I may be wrong about the reason being the WTF change- meld-" improvement".

But hopefully, no one else had similar issues with the CONcast ‘improvements’- especially since nowdays without a smartphone assumed to be on and in use 24/7 and used for text ( not me ) one simply does NOT exist in this world except for joining the civil war vet voting cadre.

Did this happen to anyone else ?