Welcome to the future :)
So we effectively have a custom domain in gmail, for sending and receiving.
As far as the internet is concerned we are one entity with multiple devices.
I will never use a Google service as a mission critical part of my life ever again because of all this, they just have no interest in customers.
A simple solution would be "well make reliable products then", but of course that's not free either.
At least, that was the case when I got rid of my Pixel 6 months ago in favor of an iPhone :)
Slowly migrating everyone off of it and just keeping it for single email address list distribution for family emails.
I had a very, very hard time getting them to forget about my domain so that it would work elsewhere
I would like to, and plan to, leave, but for now, this is the better way.
Very little work is done there.