I don't know whether you are experiencing this issue or not. Its strange, the 'Site Pages' library behaves differently whenever a page is deleted. When a page is deleted, it displays the shimmer and it is not refreshed unless the whole page is reloaded. I am using the default modern site pages library without any customization done to the library or views etc. Please look at the screenshot below
@Sudharsan K Hi, This is occurring currently in Site Pages library and in other Document Libraries and Lists as well mainly in grouped views and it displays shimmer when item is deleted in grouped by CreatedBy column and ModifiedBy column scenario and in other scenarios of grouped by other columns, the view doesn't remove the item automatically after delete and requires manual reload.
The non-grouped views doesn't have this issue and gets refreshed automatically after deletion. Are there any errors generated in your browser console tab?