Internet explorer not finding right content from multisite

Okay, so this is at weird one.
I only encounter this issue in IE and no other browser.

I have a wordpress multisite installation where I have content on:
example.com
and
example.com/sub-installation

So there is a front page when a user accesses:
example.com/sub-installation

The front page does show up when you access it.
However, the content of that page is supposed to change if the user is logged in.
SOMETIMES that content won’t change when the user is logged in.

When I click F12 and check the Network tab, it seems like the issue occurs because the browser tries to access a sub-page to example.com and not example.com/sub-installation:

When it looks like this the page works as intended:

Is there a way to prevent this?

Does anybody know why it only does this sometimes?

I figure that I could just change the URL for the sub-installation, but is there anything else or?