Drive belt broken?

[Kirky72]

Over the last few rides in Zwift it feels like trainer has lost a lot of resistance, I spend most of any route in the big ring and bottom cogs, sharp rises like coming out of the London undergrad at 15% used to need small chainring and 26/28 cog now if I drop into that its impossible to create any watts and momentum, can climb it in the big ring and hard gears.

I’m spinning out on most downhills and I have the realism or effort at 100%.

I haven’t suddenly increased my ftp to 800 or become a climbing god so expect the belts stretched or slipping. I have calibrated and get the usual reading and that everything’s okay but the calibration only lasts a few seconds with not much peddling in the elite app.

Anyway to contact elite tech people as can’t find anything on the website.

Any advice on how to find the exact problem and fix it?