Hi, I think you have 2 issues, first the sound and second the “waiting for audio engine”.
Regarding the first, you use your Focusrite via the Generic Low Latency driver, but you better use the dedicated Focusrite ASIO driver. Try that one out and see how it goes.
Regarding the second, you use HALion Sonic 7 and get hangs of the audio engine. This topic has been already discussed and a workaround is described in this thread.