Erg mode differences between apps

I’ve been a TR user for a few years. Just stopped using them and started with Xert. I train outdoors mostly but use a SAris H3 when indoors. With TR the control was always responsive and smooth. With Xert over noticed it lags a bit after you pick up the cadence to adjust power/resistance.

Today I was doing an endurance ride and I was to hold 215 which is pretty easy and what I normally ride 3-4hr rides at. It felt like I was pushing over 300 watts!!

I switched to TR just to do an RPE test. Set an interval to 215 and it felt as it should. Way way different

Any thoughts??I love Xert so far but need this to work. This power is all through the H3 no PM on that bike.