Started about 3 months ago with the loss of powerups.
Then wattage got screwy.
Plus now, no drafting.
The 1st and the 3rd point to you using the Zwift TT bike in-game. As for the 2nd more info is needed.
Accually more info is needed for all of it.
Yes, due to the speed the TT bikes offer they have never allowed for powerups, nor drafting.
As for wattage being crazy, as Paul mentioned, I think we might need more details there. What computer/device and powermeter or trainer are you using? If its ANT+ I’d suggest getting the USB ANT+ receiver close using a cheap usb extension cable. If it’s bluetooth, maybe we can try pairing a different way once we know more about the setup.