My Zwift ftp is too high and won't let me correct it

I started riding on zwift about a month ago. I am by no means a strong cyclist (45m, 5'10", 220lbs) and am rehabbing spinal stenosis.

Zwift has set my ftp at 307. I have not done the ramp, but have done the grade a few a times, with a pb of 29:48 and 180 watts. My 20 minute wattage high is 187.

I have gone into the game multiple times to set my ftp in my profile and it saves like everything is cool. But, that gets tossed out and after I ride, my ftp shows back up at 307.

Anyone know what might be going on?