If your FTP was right in the 1st place, then you would feel approx the same after each work out, since all intensities are based around this number, i.e. as you FTP goes up, workouts don't feel that much harder, because they are in relation to your current fitness. I would guess that if you have noticed a big jump, it is because the original value was way off.
I am not sure about the Trainer Road FTP test, it is not the same as the ones recommended by Allen and Coggan or those by Joe Friel all of which require at least a 20 minute TT effort on all variants. The trainer road version is a couple of hard intervals and then a pair of 8 minute efforts right?