I get inaccurate readings when wearing my Whoop on my wrist when cycling (or anything else where my arm/wrist was mining a ton or getting bounced around. I went back to wearing a Garmin Tickr HR strap on rides and also eventually got a Whoop bicep strap. I’ve done many rides with both the Tickr stap and Whoop bicep band and the min, max and average HR numbers are constantly within 1 or 2 beats of each other. I’m confident enough in the wrist strap accuracy when sleeping etc to use the HRV etc data but it reads high on the bike.
I love my bicep band. I wear it most days as I like wearing regular watches and don’t want something on both wrists.