Environment: InDesign 2020 or 2021 (16.3.2 or 15.1.3 Japanese version) + macOS 11.5.2

These are the steps:
1) Create a new document, create a graphic frame on the first page, and place an image on the frame.
2) Add a tag to the graphic frame. (For example, "root")
3) Lock the graphic frame.
4) Add one page.
5) InDesign crashes when you delete a page with a graphic frame.

Here is a file that can be reproduced.
https://shared-assets.adobe.com/link/e107f135-8305-49bf-7c71-9e62466d1bea