Error loading Google resources by bot (or "other error"). How to decide?

Question

Google

Often when checking the site with Google tools in the webmaster "URL Checker" or in "mobile-friendly".
We have a problem with loading resources: js, css, images.
Moreover, the tool itself writes a vague wording "Another error". Judging by the screenshot that Google itself makes, it can be seen that the styles and images did not load.
The site runs on Bitrix CMS, BitrixVM runs on the server, there is enough power.
1. What is the problem and how to solve it?
2. Does this affect the promotion and position of the site in search results?

Answer 1

The problem with the Google robot, it saves resources when checking the page: time and traffic.
1. The page (html code) should be short, up to 1000 lines of code
2. Connected resources should load quickly and be lightweight.
Large sites solve this problem through CDN - the robot allocates additional resources to crawl a third-party site. And the styles are not loaded in a separate file, but in the head in the style tag.
My solution was different: initially, when the user visited the page, the first 10 pictures were loaded via lazyload, and the pictures for the bot are quite large: 350 x 350 (products). By reducing the number of images uploaded to 6 (120-200 kb and 100-200 ms savings) - it was possible to almost (there are exceptions) completely get rid of such a problem as "another error".