What are the strange errors in Google Merchant Center?

Question

Google

Registered and verified an account in the Merhcant Center. Half of the products are approved, half are not.
Errors and claims from Google:
- Inaccessible mobile landing page - all product pages are opened from any device - I go to this notification - writes - "Robots.txt reading timeout";
- Wrong value [accessibility] - checked, everything is correct;
- Inaccessible desktop landing page - all product pages open from any device - I go to this notification - writes - "Robots.txt reading timeout".

Has anyone experienced this and how can I fix these warnings?
Thank you all in advance.