Unable to stop Outlook mail from forwarding to my Gmail account

Hi, hope someone can help please. 

Previously enabled forwarding in my outlook to my Gmail. However, after I stopped the forwarding, the forwarded email did not stop. Check with my wonderful IT folks and they confirm that all server rules for forwarding are absent. I am stumped, as are the IT folks. I'm an end user, not an IT specialist.  

Checked for solutions but so far no joy.  found these and they don't work

https://answers.microsoft.com/en-us/outlook_com/forum/all/i-cannot-stop-having-my-email-forwarded-from/a7db8308-9250-44d6-942d-398a3d177f1f

https://answers.microsoft.com/en-us/msoffice/forum/all/i-cant-stop-office-365-from-forwarding-emails/54e8cd86-e887-4bd4-ba95-41c3c9e5897d

https://answers.microsoft.com/en-us/msoffice/forum/all/please-help-i-cant-stop-forwarding-emails-from/7c93d4bd-6adf-4913-b6d0-8371be9f7cae

Have tried the suggestions:

- disable forwarding in outlook.com (I use outlook.com for email)

- disabled all forwarding rules; in Outlook and in Gmail

- checked that Gmail isn't pulling email from the Outlook account

- yes, I clicked the 'gear' icon in Outlook (we are using Office365), went to mail, and clicked 'Forwarding' under Accounts and the button to Stop Forwarding' is black.

When I try to insert a new forwarding email address, the Outlook mail forwards to the new address and no longer the old Gmail address.

However when I click 'Stop Forwarding' in Outlook, it reverts to forwarding to the old Gmail address even though there is no longer any email address in the forwarding setting.

Screen shots of Outlook forwarding disabled and Gmail not pulling email is attached.

Also, cleared cache, tried fresh installed browser on a spare machine. no joy.

- rules and alerts- checked

-Gmail pull email- checked

- Outlook forwarding- checked

Any suggestion is most welcomed.

Thanks!