google webstory preview and publishing blank page

After creating my first content for webstory, when I try to preview it shows a blank in my website. sample is given below:-

I read forums related to webstories on wordpress and tried advices given like installing Health Check & Troubleshooting plugin. > activate it> enable webstories plugin > and checked if the webstory could preview but the same problem persists in default theme. Then I rolled back to my installed theme.

I have the below relevant setting in my webstory.:-
Stories Archives – set to default (I don’t know if this is casing problem)
I have the below message shown in plugins page (letting you know if this is relevant) :-
Rank Math has detected a new post type:?web-story. You may want to check the settings of the?Titles & Meta page?and?the Sitemap.
It is killing my time. please suggest me some solutions.

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