The issue is with category pages not showing on AMP is as @lofesa mentioned it is related to Base category name is missing from the permalink.
But to solve the issue we have released a free extension which you can download from https://ampforwp.com/amp-category-base-remove-support/ and it will fix this issue.
As you mentioned previously it used to work when we used to add “?” and there were some issues with it and we totally updated that code and made it pretty permalinks supported. After this update, your category pages which does not have category base would have stopped.
Please install the above-mentioned extension and all your AMP pages will work without Category Base as well.
Mohammed Kaludi
]]>Could you elaborate the GWT part?
Regards,
Ahmed