Delay when pedaling

I’ve just started using zwift so I’m not sure if this is normal or not.
If I am stopped on a flat bit of road, when I start pedaling it takes a very long time for my avatar to start moving and for the watts to increase.
Even spinning very fast in my highest gear it seems to take ages for it come up. I am using a Elite Digital Smart B+ wheel on trainer paired over bluetooth with a windows 11 laptop.
My wheel doesnt seem to be slipping on the roller or anything.

I had the trainer paired as a power source, a cadence sensor and a “controllable”. I unpaired it as a cadence sensor because that doesnt seem right (how can the trainer know my cadence without knowing wheel size and gearing?) and I have the same issue.

This also happens if I suddenly increase my speed while already moving, there is a very long delay before the watts increase.
It really really seems like the wheel is slipping but it seems to be fine.

I haven’t ever measured power and cadence before so I don’t have a reference to gauge if these seem right when I am up and moving

Is this something I can fix or is it just a limitation of the trainer, its probably the cheapest you can get so I would have expected some drawbacks.
I’d be very grateful if anyone has some suggestions.
Thank you

My first troubleshooting step would be to pick up an ANT+ USB stick for your computer and attempt to connect the trainer over ANT+.

Call it a hunch - I’ve read more than a few accounts of BLE potentially being laggy. I might be wrong but it’s an easy thing to test.

Alternately, find/borrow a device with ANT+ (top-tier Samsung Galaxy phone) and test this solution by running Zwift on it.

This is a red herring. Trainers have all sorts of ways of calculating cadence such as measuring power phase (they know when you’re pushing). Some even have cadence sensors built in that detect your pedal moving past. Regardless, it has no bearing on the game: the trainer is simply including cadence data in the stream of data it sends, along with power.

Slightly off topic - but trainers can calculate cadence in a few ways, it is more of an estimate and some do it better than others. They look for spikes in power and work out your cadence from that. when you’re at the top of your pedal stroke and push down you have more power than the rest of the pedal cycle, so it looks for these spikes and then uses this to estimate your cadence. there should be two of these spikes for each rotation (one left, one right)

Hi thanks for all the responses.
Will try ANT+.
That’s interesting about the cadence measurement. I’ll switch that back on