Different speeds with the same ratio

I was asking you if it happens to you too to do different speeds (even a lot) with the same ratio / cadence.
Many times I see that I go downhill at 55 km / h with the 50x15 at 80 rmp, other times I find myself on the flat at 42 km / h with the 50x13 at 80 rpm.
It’s possible?
I have a perfectly calibrated Elite Direto XR trainer, the resistance seems to work properly uphill, but downhill it’s not free enough.
Another thing: does it happen to you too in the curves to be thrown outside furious from the curves? It always happens to me, I see the compact group in the center and I who adhere to every curve go outwards out of the wake.

Check your trainer difficulty setting, it’s a slider under settings that you can access while in game. I leave mine at about 35% so I can do almost everything in the big front ring and it flattens some the inclines but raising it will increase uphill resistance and lower the downhill resistance. Remember it will not affect you wattage regardless of what setting you use just the feel and your gearing. Just an idea.

@Stefano_Moser1 - this vid might explain a bit for you.