Did the ramp test actually stop? Is that what happens in Zwift? 250W sounds very low if you were set at 190W previously. I think when I do a Half Monty (SYSTM version of ramp test, with added 20 mins of sustained effort) with an FTP around 300W, I don't 'fail' until I'm touching over 400W (which SYSTM analyses and says 'yes, your FTP is 300W ish) so for the test to actually stop at 250W seems odd? (Mind you, I guess proportionally, 190 to 250 is almost the same as 300 to 400?)

(Or for a baseline, various things, I think including Strava, will show you your power curve. Check what the best 20 minute power you've ever done is and multiply it by 0.95 for an FTP)
