Pictures fail to show due to switching pathway – Image File vs Attachment Page

Occasionally, website loads all pictures with wrong pathway, and they do not display.

Problem occurs occasionally but only when viewing a post that has never been loaded before.

I choose to link to image file when uploading, ie: “https://website.com/wp-content/uploads/year/month/name.jpg”

But when problem occurs, the pathway shows “attachment page” style, ie: “https://website.com/page_name/sony-dsc-21/”

This problem corrects itself only if the page is refreshed. It seems to occur randomly, and has happened to other people who is visiting my site.

Any idea why it is occurring? Website in question: https://0thmirageknight.com/