just chiming in, i have the same issue. for SO long i've had microsoft ask me upon logins whether I want to use my personal or a workplace account. apparently at some point for some reason i created a workplace account to test something out and used the same email address I use for my microsoft account.
I always choose personal and the prompt for the "other" is an annoyance but so far hasnt caused me any issue beyond that i know of. I did try to log in via "workplace" here or there to see if i could change or fix something but it always fails/wont work. Makes sense since there never was a workplace but i digress.
either way i now have the same error and every time i click the sign in box I get this