Doesn’t matter if backpedaling is recorded or not, or what is displayed on TR app during the backpedal. It seems that is the source of your confusion.
If you are approaching failure during a work interval, then backpedaling may help you continue the interval to completion. Again, forget about what you see on the TR app while backpedaling. The goal is to complete the hard intervals, and if needed go ahead and take short 15-30 second “micro rests” so that you can get thru the entire hard interval.