I would recommend that you just ride for a bit, don't worry about trying to nail your FTP. Go do some longer efforts the old way and just collect data.
I'm fairly good at VO2 efforts, so I can put down a good 20' effort, and can really ramp it up in the last 8-10 minutes. Because I excel at VO2 efforts, my FTP is a lot closer to 90-92% of my 20' test power, rather than 95%. I really don't like to do 20' tests to estimate. I prefer to do a 2 x 20' workout with a very short 30" rest in-between. It's not uncommon for my mental desire to be less than my physical ability, so I often hit the lap button at the 10' mark, and continue to push on. I can more easily tell myself I can get to the 10' mark rather than continuing to watch it count to 20'.
Also, if you do a 20' test to estimate, make sure you follow the protocol and not just try a 20' max effort. There's a 5 minute effort beforehand, and IMO, it's important to not skip that.
I'm fairly good at VO2 efforts, so I can put down a good 20' effort, and can really ramp it up in the last 8-10 minutes. Because I excel at VO2 efforts, my FTP is a lot closer to 90-92% of my 20' test power, rather than 95%. I really don't like to do 20' tests to estimate. I prefer to do a 2 x 20' workout with a very short 30" rest in-between. It's not uncommon for my mental desire to be less than my physical ability, so I often hit the lap button at the 10' mark, and continue to push on. I can more easily tell myself I can get to the 10' mark rather than continuing to watch it count to 20'.
Also, if you do a 20' test to estimate, make sure you follow the protocol and not just try a 20' max effort. There's a 5 minute effort beforehand, and IMO, it's important to not skip that.