I hope you are doing great. I had a similar issue past month and this is what happened:
I had 8100 4.1 OS and upgraded to 4.5 using this forum indications (with DM 4.6), later I bought an 8130 and used DM tool “Device Switch Wizard”. I had a lot of problems using this tool, but finally I got to transfer my entire data but OS version, so downloaded the 4.5 for 8130 and followed previous instructions. Not worked (never prompted DM for updating device).
Kept trying to find any solution on the forums but had no luck
I resolved it by uninstalling DM, deleting all registry keys and backup DBs and loading everything again. (Did not erase anything from 8130 with all my info)
After installing DM and trying to update OS, everything worked
Hope this helps.