No, unfortunately we can't.
Right now everyone lost track on what connection you use between your WiiM and your Yamaha.
You posted information like the optical out of the WiiM was for your turntable only and that you set the WiiM audio output to Airplay. Frankly, none of that makes any sense, neither individually nor in combination.
Your WiiM needs either an analog connection (WiiM line out to Yamaha line in, but not phono in) or a digital connection (WiiM coax out or SPDIF out to Yamaha digital coax in or SPDIF in) to your Yamaha. The audio output setup in the WiiM Home app on your phone must be set to the one output used, exactly. Either line out or coax out or SPDIF out.
If you use the analog line out, you can configure the maximum output voltage in the WiiM Home app on your phone (setting the lowest possible value is the safe route for testing). If you use one of the digital outputs instead, you can configure the maximum sample rate and bitrate (again, the lowest values are safe for testing).
Your pictures seem to show that there is an optical toslink SPDIF connection between your WiiM and your Yamaha and you mention the Audio 1 input. However, in the same post you talk about Audio 1 as being a coaxial input, which it isn't. This makes it very hard to follow what you are actually doing.
It would also be very helpful if you could permanently keep the turntable disconnected from the WiiM until the issue is resolved. Nothing should be plugged into the WiiM but the power cable, the network cable and the optical toslink connection going to the Yamaha.
When you have been connecting the WiiM line out to either Audio 3, Audio 4 or Audio 5, there had been a theoretical chance of an issue with the Wiim putting out DC voltage or just too high AC voltage. This is absolutely impossible using the optical toslink SPDIF connection since it is not an electrical connection at all. There's nothing the Yamaha could protect itself from. It could only not be supporting the sample rate and bitrate you set up in the WiiM Home app on your phone.
You also never told us if this setup has ever been working during the previous months since you own the WiiM. So, did it work fine at any point in time before? If so, what did you change in your system before it stopped working?
Please understand that this is not WiiM support. We are all just WiiM customers trying to help out other WiiM customers. We don't really care if you are not satisfied with any WiiM product (*), we just want to share our experience and try to get your issue solved, if this is possible.
(*): I take this statement back and now declare that I personally don't care if you are not satisfied.
