straid, in Version 5.6.0, the UPnP processing has changed dramatically to meet your needs. The internal processing, which contains temporary statements, has been rearranged, the decoder for HTTP service has been relocated. I have tested that it works on my test devices. There is no going back.
I suspect that the TuneBrowser change is having a negative impact in your environment, but I can’t address it because I don’t know what is wrong with TuneBrowser (if the TuneBrowser is sending UPnP messages that are not compliant with UPnP regulations, please let me know the message. I’ll check it).