AMP Pages not loading on Iphone

I am facing peculiar problem. I have installed AMP two weeks back.

1) When I go through google search (through Google search App), the AMP pages are not loading on some mobiles. e.g. Iphone. e.g. I type myinvestmentideas in google search option and my website appears on first rwo

2) It show the AMP icon in google search results and when I click it, it takes to blank page of website.

3) When I view the URL of the blank screen, it shows the website url, but without AMP (amp/ not in link).

4) If I click on URL link and say “Search” button in iphone, AMP pages load directly from website (not from google cache).

This is not just happening only for home page of URL, but with all AMP pages. None of the AMP pages are opening on iphone if I go through google search (I have Iphone 11 and latest softwares installed).

Strangely, if I open Iphone Safari or Google Chrome, these are working fine.

I wanted to know if there is any compatibility issue of AMP with Google Search App of Iphone? I am yet to check various android mobile phones if we have same issue.

I have cleared cache / history / restarted mobile couple of times to check if this caching issue, but still not working

I am attaching screenshots for quick reference. https://imgur.com/a/KLMld3R

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