Split from this thread.
I am having the same issue. This has previously worked with no issues; however, over the past 4-6 months, I have noticed this issue.
In response to your follow up questions.
When adding the link to the Quick Launch menu, I paste the URL and then click the "Try Link" option and it works as expected. When I click okay and then click save on the Quick Launch Menu, I will try the Quick Launch item that I just added. When doing so,
the screen will simply reload to the current page that I am on. When I attempt to edit the link again, I have noticed that the link has been changed/truncated from what was previously input. For example, when I copy/paste the original URL, it will begin with
https://sitename.sharepoint.com/:o:/g/...... After saving, this portion is stripped from the beginning of the URL.. The document I am trying to access is a OneNote Notebook and is stored in the SiteAssets folder for the same Site that I am currently in. I
have attempted copy/pasting the URL in a separate browser and used the "Try Link" option, which both work. But, when it is saved, the begining part is stripped off, it no longer works in any manner.
I have attempted to reedit the URL to add the beginning portion back it. It continually will strip it out when saved.