I’m having some issues, I think, with zone detection, both cycling and running.
I have had my 1st trainer w/ power for about 8 months or so. Pretty quickly it seems the zones that were suggested matched my feeling of what each zone should feel like (RPE, endurance & tempo heart rates), and the estimate of my FTP [172w] from my head unit. 
But, a couple weeks ago I did one of the ramp tests, and this is where things went off the tracks. Essentially, it suggested that all my zones should be increased by about 50 watts. I repeated the ramp test the next week and couldn’t do the same number of steps as I did the first time. I was able to complete the 240 watt step, and failed on the 250 watt step.
So far I have decided to ignore these new zones.
[I have had some issues with zone detection for running too, but I’ve decided to focus on cycling here to not confuse the question]
What to do in this situation? Explicit fitness tests, more racing, something else?