First, this is a wonderful forum and as a lurker, I've learned so much here.

My Q10 pro was previously running firmware version
1.06 and Kodi 17.4. An HDMI 1.4 cable connects it to a Denon AVR-4810 receiver powering a 5.1 system. Another similar cable connects the Denon to my Sony 50W800C TV. Aside from known bugs, I've been generally happy with my Q10 Pro. I have it playing Bluray rips from Windows SMB shares
(no password) over the home gigabit LAN. No stutters, no buffering. My old Denon passes 1080p and decodes Dolby TrueHD and DTS HD Master. And as an Android box, I don't use my Q10 Pro for anything else except to run Kodi.
Last week I replaced my TV with an LG OLED 65E7. My old old Denon doesn't not support 4K, so I set it aside and ordered a Marantz SR7012 receiver. It hasn't arrived yet, so a new 4K60Hz-rated HDMI 2.0 cable connects the OLED TV directly to the Q10 Pro. After setting the resolution of the Q10 Pro to 2160p, 4K rips played just fine.
My problems began today when I decided to upgrade the firmware to version 2.05.
Of course, I read and followed all the steps, going to version 1.10 first, then 2.04, then 2.05. I didn't bother to test Kodi playback between upgrades, nor did I bother to back up my Kodi library or anything else since I had just rearranged the movies folder on my computer following the addition of new Western Digital MyBook external drives.
In short, the wrapper wouldn't work when playing videos on the Kodi app that came with firmware 2.05. I properly set up my Samba shares and waited for the library to finish populating. But select a video and it would just ask me to hit a button on the remote once video playback ends. No actual playback happens, no matter what I tried.
So I looked up and followed the procedure to downgrade to Android 5 and now wrapper works. The firmware comes with Kodi Jarvis, so I upgraded to 17.4 from the Play Store. Wrapper still worked. Everything plays, including 4K videos after setting the resolution of the Q10 Pro to 2160p. I didn't have to run the wrapper app at all, nor mess with its settings. It just worked. This gave me some confidence, so I decided to follow the prescribed procedure and upgrade to firmware version 2.05. Sadly, wrapper wouldn't work.

Now my Q10 Pro is using the firmware that allows a downgrade from 2.05 to Android 5. For me, this firmware is reliable. All I did was properly set up my Samba shares in Kodi and wrapper just works. No messing with any wrapper settings, at all. And for the incoming Marantz receiver, wrapper
has to work as Kodi alone still won't pass 7.1 channels over HDMI.
So my question is,
what did I miss?How can I get wrapper to work with version 2.05?
Thanks, guys. Appreciate your help.
