wordpress attachment url change itself

I always set attachment files as attachment links url in wordpress as i prefer the shortform version of the url

so the url should be like this example;

<* a href=”xxx.com/?attachment_id=49″ rel=”attachment wp-att=”49″>file *

but after clicking post, the links auto change itself into file name

<* a href=”xxx.com/category/post/49/attachment/filename/” rel=”attachment wp-att=”49″>file *

even if i re-adds the file it wont go back to simple url. it will stay in form of the new url. anyone know what’s causing this?

In case you don’t understand what i’m saying pls check the image below

https://i.imgur.com/WnkMFrW.jpg

View post on imgur.com