I have an initramfs for you to try that should fix this problem. You can download it from here:
rbp1:
http://collaborate.osmc.tv/index.php/s/OkpI7MylULUyF1Y/download
rbp2/vero:
http://collaborate.osmc.tv/index.php/s/q7fxVeIlDzMA1v6/download
Download this file and save it in your /boot partition named as initramfs.gz
Then edit your config.txt to include the following line:
initramfs initramfs.gz followkernel
This will tell the kernel to use this external initramfs instead of the one built into the kernel image. Then edit your cmdline.txt/uEnv.txt to put back your root=UUID option. This should fix the issue with UUID detection. Please let me know if this works for you.
This fix will be included in next months kernel update so please remember to remove the initramfs line from your config.txt after updating to next months (December) release so that you don’t inadvertently continue to use an out of date external initramfs.
Also please take care not to enter the Pi config and overclock modules in My OSMC as it will remove the initramfs line from config.txt. (It doesn’t currently understand options without an equals sign) If you do by accident, edit config.txt to put it back before rebooting.