Same issue. I rely on this heavily! JavaScriptCore`invocation function for block in Inspector::RemoteConnectionToTarget::dispatchAsyncOnTarget(WTF::Functionvoid ()&&):

Found a workaround. Setup a new simulator with the older iOS. 14.3 works, 14.5 doesn't. Feel free to send over promo codes to your apps in appreciation!

Use the "Download Simulators" menu and download a previous version of the simulator as I outlined above.

you need to downgrade, not upgrade.