I viewed a report via a link that was shared with me by Misha. It was not intuitive that in order to then customize it, I had to click the "Clone Report" button at top.
Even Misha's instructions were to click the edit/pencil icon on right which I didn't have so it took back/forth to know how to make the filters appear and editable.
Unsure how best to solve but expectation would be some indication to make it editable or toggle on/off the filters. (Edit or filter icon)
You could display them as disabled with a tooltip to say "this report is read only but to edit filters, Clone Report above"