Exporting and then re-importing a configuration can cause warnings during the backup if you change the type of the destination. E.g. exporting a configuration with WebDAV destination to a file, re-importing that configuration and changing the destination type to google drive.
The “TargetURL” in the config retains the previous WebDAV auth-username= and auth-password= parameters even though these are not used for google drive.
The backup still works but you get warnings in the backup log:
The supplied option --auth-username is not supported and will be ignored,
The supplied option --auth-password is not supported and will be ignored
Ok, after messing around I found that you can go into the configuration of the backup currently set to google drive and under the destination tab click the hamburger icon (the 3 vertical dots) and copy the current URL to you clipboard. Then delete the end of the URL “auth-username=CPT_Tater&auth-password=mypassword”.
You can also do what gc1 said and just change the source to a local device and switch it back to google drive before running a backup.