USB Suspend Not Working unless WiFI activated and toggled after restart

Hi, I am new to Roon and RoPieee and loving it! Due to my Noob status I am not sure if I missed a step, but I found an issue with USB sleep and my new Topping D10s.

I was unable to get the Topping to go into USB Suspend mode after setting USB Suspend in Advanced Tab. I tried multiple reboots & different USB ports with no success. I was trialing on a Pi 3B+ with the XL image and thought that maybe a Pi4 was the answer since I was using the wired network. So bought one of those rare Pi4s. Still no joy getting the Topping into sleep mode. This time using the standard RoPieee image.

I then thought to try WiFi with the Pi4. I enabled WiFi. No USB Suspend.

I then connected the RoPieee to my WiFi network. Wow! to my surprise the Topping displayed — and then a few moments the Topping suspended. I played, it woke up, I stopped the music, Topping displayed — and then went into suspend. Now we’re rocking!

I then went back to RoPieee WiFi and set the WiFi Interface to not set. The Topping would still suspend. I note that after a reboot the interface defaults to the embedded WiFi Nic but my WiFi network is not selected. The suspend still works and confirmed using the wired network interface.

I then repeated the entire process with the Pi3B+ and it too reacted the same.

It appears that you need to initially connect a WiFi network to get the USB Suspend to function. Is this expected behavior?

I created a send feedback 51feb6094f6c796b

EDIT: Sent too soon. I just realised that after a power off or reboot I need to disable and re-enable WiFi for USB Suspend to start working again. It is on the re-configure that the suspend function starts working.