I have the same issue. has there been any solution or can I ignore that message (BTW: similar thing happens with BigSur)

Hi, I have created a minimal Swift package that reproduces the error-message. Maybe you can have a look at -> https://github.com/thieso2/WebSockDemo and Thank you for your support! Stay safe! Thies from Germany.

Hey - just checked my provides sample project on current 11.1 (20C69) Maybe you can have a look at ->  https://github.com/thieso2/WebSockDemo it still prints that message and, I believe I followed all your advices. I'm pretty sure you'll be able reproduce the problem by running my code. My Question: Can you either confirm that you do not see that message when running my code -or- provide a complete runnable sample that works without emitting this message? Thank you & Stay safe! Thies

I filed a ticket with DTS, and they basically told me that "The behavior and resulting limitations you describe are by design. Safari Web Extensions must be distributed via the AppStore." I remarked that this behavior is different for Safari App Extensions (old style) that do load and work when the container-app is notarized. I was told this about Safari WebExtensions: "It is not a bug as they were never intended to work outside of the AppStore" All I could do was to file an Enhancement request. Personally I still see this inconsistency as a bug.