I think i found a solution. On your iPhone: Go to Settings, then tap General. Tap Transfer or Reset [Device]. Tap Reset, then tap Reset Location & Privacy. Now the link between your iPhone and xCode is removed / untrusted. Make sure you have your apple watch selected as active watch in the iphone Watch app. Now open xCode and connect the iphone with USB cable. The "do you want to trust this device" alert should pop-up on your iphone again. Select Trust device. Give it a bit of time, and once your iPhone becomes available as destination, your AW should also pop-up. At least this worked for me.

I'm having the same issue. Since exactly 15-06 I only get Timouts. Not a single response anymore. Locally (From postman it works). But from my Google App Engine it does not work anymore. It almost looks like my GAE IP got banned or something like that. I thought it was a rate limit issue, but it's not. Big problem, no solution?!

Same problem here. We have an activity tracking app and people lock their phones to go out with it. We have advanced tracking based on raw sensor data and this uses more than 15% CPU. IOS 14 no problem. Also IOS 15 no problem with iphone 12/13, because they have more CPU resources and we stay under this new/undocumented limit. If you google you only find the 80% limit in the official documentation. Very annoying, our app is now not working anymore expect with Guided Access. Guided access is not really a solution though since it drains the battery because the screen stays on. Any work arounds would be awesome if you know one. I'm currently testing to play some audio because maybe the % limit does not apply to audio apps.