Short links generated by wordpress is not working for post permalinks like this:

https: //www.mysite.com/test/mypage

It\'s working if the permalink looks like this:

https: //www.mysite.com/mypage

In both cases I get a short url like this:

https: //www.mysite.com/?p=123

Or

https: //www.mysite.com/3BmdT (If I use a plugin: Shortn.it)