Kodi 17 Krypton Upgrade Stalls Add-On Migration

Perhaps someone can assist me
I am have repeated inconsistent errors of Kodi Krypton upgrades stalling at “Add-On Migration in Progress”
Boxes are fairly standard OS 6.1 such as “Sunvell T95X Amlogic S905X Android TV Box – 2GB + 8GB US PLUG 1” in both 1 gig and 2 gig configurations
Devices are “Rooted”
Sometimes the boxes will upgrade to a screen – being unplugged and restarted repeatedly
Other times the boxes will be active yet continuing to exhibit the working error “Add-On Migration in Progress… please wait ” with the kodi box still upgrading and active ( i.e. not frozen)
The boxes have been reset to factory defaults then set up in Kodi 16.1 Jarvis and then upgraded via a standard Google Playstore upgrade
The upgrade process will give errors of “Kodi is not responding Do you want ti close it ?” Wait or OK which closes yet if left the add -on migration process seems to continue
Perhaps a file of Kodi 17 Krypton should be used instead ?
Any tips ?
Some of my tests will upgrade others are stuck at the add-on migration in progress stream
Thank you