Unlikely, I understand they basically share the same codebase for common functions. What UPNP server are you using?
Bubbleupnp on Android is largely accepted as the best upnp client app - if you use that instead of the WiiM Home app to play to your Mini, do you get better results?
I tried basic Windows DLNA, and Foobar 2000 on my laptop. I also used Bubbleupnp on my Fiio M11 plus ESS (android based portable Music player)
Using the Fiio M11 with Bubble UPNP as the server AND controller to play music to the Wiim Mini works well. But I wanted something that will work with iOS, as all my other devices are Apple, for which Bubble UPNP is not compatible.
I did try using the Bubble UPNP in the Fiio as the server, playing to the WIIM, controlled via Wiim app on my iPhone. As described in my initial post, the Wiim app only plays a fraction of the available tracks. Same results with using laptop as server, playing to Wiim, controlled via Wiim app on iPhone.