Welcome to the forums, and sorry to hear this. Your poor legs!
There were no intended changes to power/resistance, in our last release.
I will review our recent code changes for possible side-effects, and alert our QA team.
I have a favor to ask of you and others when reporting Resistance issues:
Could you please include Platform, Trainer, and Pairing protocol (ble vs ant)?
Our game uses 3 separate low-level bluetooth implementations.
One for Mac/iOS/AppleTV, one for Android, and another for PC.
Some bugs are cross-platform, others just affect one platform.
If an initial report contains the Platform, Trainer, and Pairing protocol, it can really help our forum community.
And to be fair, some Zwifters may not be aware that the game even exists on other platforms!
Thank you again for your post and hope to hear back soon with those details.