I’m experiencing a similar issue! No problems with the file path though:
For me, the problem is that I want to highlight a selection, and then hit my hotkey for Add internal link.
However, when I do so, the text inside the double brackets becomes greyed out and unresponsive, and I have to type an edit to it before I get the typical autocomplete dialog.
This was a massively convenient small feature for me! I hope it can be fixed soon 