balinsa

Finally I got the problem solved, here is my experience:
– in pages, if I want to use post or post items, I create a loop object with tags_post_id=0 parameter first, and then insert the loop object into pages. It is not viable to insert html with shortcode directly to a page for post function
– in post, I can insert an html element directly with shortcode.

I have solved the problem, but I don’t know what I have done to cause the cure. I observed some php error logs about RankMath, my SEO plugin. So I disabled it – and the issue was solved. I reasonably think there is a conflict between Tag Groups and RankMath, but after I reactivate RankMath, the previous issue is gone, and I cannot repeat it anymore.