When a Store account has troubles syncing with the game, please follow these troubleshooting steps:
Android:
1. Go to your Phone Settings.
2. Find and select Google / Google Services.
3. Scroll down and select "Settings for Google Apps".
4. Select "Play Games".
5. Click "Change account for games".
6. Scroll down and select "Change" next to Catalyst Black.
7. Select the Google account which you linked the game with.
8. Open the game.
iOS:
Please try to sign out of your Game Center Account.
Afterwards, kindly wait a few minutes and try to log in again.
If the steps above fail, do let us know by contacting us here: https://catalystblack.zendesk.com/hc/en-us/requests/new.
We'll assist you!