Mythic score for main isn’t updating. It’s over 1000 (needed for upgrading items) but shows 458 (tank) on alts. Shouldn’t you be able to update faster with account information access?
Raid progress also shows 1/10 on main, when it’s 3/10. It’s been like this over a week.
Blizzards’s default UI is only applicable to the character that you are logged into. You specifically mentioned looking at your main’s score when logged into an alt. That’s a Raider IO feature, not a Blizzard feature (if you disable RIO you won’t even see your main’s score on an alt).
Try posting on the RIO forums, but generally that information about your main when logged into an alt is based on how often you get updates of the RIO database. For non-Patreons, that’s usually twice per day max per their website.