I got the replacement ** FLIR One ** today, and it ** works on FairPhone 2** 
The app have been updated while i was waiting so it is unclear to me if the problem was in the camera or app.
Played with it three times for an hour total, and it “just works”
Normally the framerate is something like 5 to 10 fps, my quick personal guesstimate.
Slight problem: sometimes with maybe a minute interval there is a one second pause in picture update on screen and while recording video. As FLIR will get a FP2 to try it out on, i guess they will have a look at that.
Versions
FLIR One, version 2
(they made a different with same name “flir one” earlier…)
Hardware revision E, firmware 0.4.27
App version 1.5
FairPhone 2 “one of the first 17418”,
no system updates i know of.
I run avast antivirus since a week ago.