It now seems easier going up the hills and a little less easy going down

I noticed during my last Zwift ride that their now seems to be less variability in the effort level required to ride up the hills versus coming down. For the first couple of months when riding on Zwift island I would usually change gears several times during a circuit of the island especially if it was early in the ride and I was warming up. During my last ride there didn’t seem to be any difference in the power level required to ride different types of terrain on Zwift Island, just a difference in speed. I much preferred it the old way.

Sounds like your Kickr got out of sim mode. Try restarting everything.