I am having a similar issue with the power being WAY too high!
I’m using the Elite Novo Smart with an iPad over Bluetooth connection. I’ve also use a MacBook Pro running macOS Catalina with Bluetooth. Zwift version is 1.0.49822
The watts go up and down just like you’ve said and can be quite random. I could be pedalling at low level cadance and gears and it’ll be okay for a few seconds (eg. 80-90w) and then after a few seconds go quickly up to around 300w and then will get stuck at say 511w.
I’ve even re-mapped the trainer using the myETraining Elite app and written in the original factory P1, P2, P3 values however I’m still getting random readings of power. I’ve tried adjusting these P values and it still causes havoc.
I’ll be trying an Ant+ dongle to see if it makes a difference but if anyone out there can help, it’d be much appreciated!
I seem to have managed to fix the issue on my end.
There’s a couple of things that I did as well as a couple of tips that I will share.
Firstly, I re-mapped my trainer through the myEtraining app over Bluetooth from my iPhone. Now, one thing to remember is that the numbers that show in the pop-up for the P values aren’t actually what’s in the trainer. They are the default values.
If you want to view/check the P values, either before or after you’ve mapped it, then if you click on the email address - firstname.lastname@example.org at the bottom of parameters page, it will show you. See the pic attached -
Now, once you’ve done this and to check it feels as it should, again in the myEtraining app, go to Trainings > Level Mode which is free and you don’t need a subscription. You can then view your stats there - speed, watts, etc.
If you click the sliders at the bottom, you’ll see that you’ll be able have a play with 16 different resistance settings by hitting the + & - buttons in the bottom right hand corner.