Gap between Watts

Hi I’ve been riding on Zwift now for around a month, I use a Garmin speed and cadence sensor 2 along with a turbo trainer, I find their is a large gap between my Wattage when keeping at the same cadence and changing up and down a gear, or when staying in gear and adjusting my cadence. For example my Wattage will sit at 137w and then the next place it will sit is 181w as you can imagine this is very infuriating when I’m ment to be sitting at 155w. Please help, is their anything I can do?

Regards Phill

What sort of trainer have you got?

It’s a Jet black z1 pro fluid trainer.

sounds perfectly normal.
if you increase the resistance and keep cadence the same, then power will obviously go up.

if you need to sit at 155w, then you either need to a) adjust your cadence or b) buy a smart trainer