If you have managed to set up your signature successfully but it got reverted automatically over night, don't panic.
This can sometimes happen if you have used other centralized signature apps or extensions. They can affect your signature even when deactivated and removing them altogether is the safest choice. Please check both options outlined below and contact us if the problem persists.
If you have lost Credits in the process, let us know, we will do our best to help you remedy the situation.
Marketplace Apps
Log into Google Admin.
Go to Apps > Marketplace apps.
Click the app name.
In the upper right of the Settings page, click the Trash icon.
Extensions
Open Chrome.
At the top right, click More and then More tools and then Extensions.
On to the extension you want to remove, click Remove.
Confirm by clicking Remove.
If you don't use Chrome, the process might slightly differ.