Power settings are way off

Maybe this has been discussed to death, but I can’t find an answer. For about 3 months I used a 20 year old mag trainer with Wahoo speed and cadence devices. For Christmas I treated myself to a Wahoo Kickr. I now know that My FTP numbers were WAY off, to the point where I am supposed to race in category A and my FTP had peaked at over 800. In reality, when I ride on the Kickr, my W/kg is more often around 1 and even in group rides/races, my watts are often around 150. As an older guy just getting going, I can live with my low current numbers, but what can I do to get rid of those insane earlier numbers? Do I just wait until they reach the 90 days threshold and drop away, or am I stuck with a category A classification forever–as I ride along at about 10 kph? Grateful for any advice.

You can contact zwiftpower@zwift.com to ask about invalidating prior results. Or wait 60 days and it will correct itself.