Now a days we found crawlling issue with google . complete website deindex and not page cached can anyone tell about this issue.
Maybe there is an issue on the website. check it once.
This means a search engine isn't able to communicate with your server. It might be down, for instance, meaning your website can't be visited. This is usually a temporary issue. Google will come back to your website later and crawl your site anyway.
If you are facing the crawling issue . Submit you website for manual crawling through search console by using URL inspection
I think there was also a de-index issue happened these past few months because there are some owners reporting the issue from different marketing forum sites.