@GaryG,
Try the following (I know you mentioned that you’ve tried this method already but please bear with me):
- Click this link to visit the gmail website - https://gmail.com/
- Once there, open your Shields panel and disable Shields (top-right big toggle):
- The site should refresh, after which, enter your login information
- If you successfully login to your Gmail account, you should be able to open and reenable Shields and, furthermore, authenticate into gmail with Shields up without issue in the future.
Didn’t work?
Instead of disabling Shields, change the Cookie control option to Allow all cookies and allow the page to refresh. Continue with steps 3 and 4.
Let me know if this resolves your issue.