Achievement unlocked bug?

Hey so I used the achievement unlocker to unlock all achievements on a second account of mine and now when I open my account in Horizon or on my Xbox 360, the gamerscore keeps getting reset to 18,397 gamerscore, which is even lower than it was before I modded it. When I go on Horizon to unlock all achievements again, it shows that all achievements have been unlocked online, but the gamerscore won’t change to the full amount, idk what this is…plz help, thanks

Delete the account and recover it.

Sometimes your gamerscore gets lower if you have Xbox One games on your profile, tends to not add your Xbox One gamerscore to your 360 gamerscore.

Delete your profile from xbox and memory unit/USB. Recover and try again.
Edit: Sniped by Chris.

Good luck!