Can you query the farFU table to see if there are any duplicate entries for /niceName in the friendlyURL column?
It sounds like there might be more than one entry, perhaps an archived URL (usually they will have a different fustatus flag to denote system generated or archived URLs), and if one of those which does have redirect set get’s cached first, and it’s redirecting to itself, then that could definitely cause the problem. So that would be step 1, check the farFU table for bad data.
If the data in the table looks fine then you might have some other kind of redirect somewhere, in your webserver config or something. It’s sometimes helpful to open Dev Tools in the brwoser, go to the Network tab, then watch the requests that are causing the redirect loop. Look at the response headers, sometimes it might give an indication of what is doing the redirect… Or sometimes not 
You’ll just need to rule out each possible layer that could be responsible for redirecting one by one. Hope that helps.