Cant log in to app store app 2018 mbp tb

[appledrone]

hoping someone can help as apple online chat after 1.5 hrs can't. Ive just bought a brand new Touch Bar 13" MBP and everything is golden, all up to date 10.14.3, all my accounts etc are working iCloud etc. When I click on the App Store app (which is pestering me to update pages etc) I click on the sign in button put in details and the box just goes as if its signed me in but it hasn't, the sign in link bottom left of app is still there and the same thing happens if I try to log in through the preferences section of the app as well. if I enter the password incorrectly on purpose I get the red writing telling me so. Apple have had me do smc reset etc, been through keychain blah blah. so annoying, literally had it 3 days, these things get less reliable every time I swear. Can anyone help?

thanks in advance

 

[macuser_123]

Try this:
https://forums.macrumors.com/threads/cant-sign-in-to-mac-app-store.2170029/

Had the same problem and this worked for me. I now have another problem in that it won't update the apps (Keynote, iMovie, etc.) it came with since it says I am not their owner (not sure what that means, they came with the computer), but at least I'm able to sign in now.