Astra Theme Pages Not Indexing

I have Astra as a theme on my WordPress site and recently Google Search Console tells me 555 pages are not indexing, I spoke to Google & they think it may be the Astra theme causing the issue as we added the Robot.txt and played with some other things in settings with no joy. Can anyone help me? I’m reasonably tech savvy but this is beyond me. Thanks

The page I need help with: [log in to see the link]