Live unit tests (tests_api) work on the previous OSX High Sierra, and MEW works on OSX Catalina (using the hijack interface and Chrome browser). Therefore, it seems that something changed with how OSX Catalina is handling USB communication with the hidapi interface. Specifically, the live unit tests fail if there is an API call to the device that requires a user touch and the user does not immediately do a touch confirmation on the device.
Live unit tests (tests_api) work on the previous OSX High Sierra, and MEW works on OSX Catalina (using the hijack interface and Chrome browser). Therefore, it seems that something changed with how OSX Catalina is handling USB communication with the hidapi interface. Specifically, the live unit tests fail if there is an API call to the device that requires a user touch and the user does not immediately do a touch confirmation on the device.