It would be good to see some logs so we can advise.
Did you try and restore a backup from the newer version of Kodi or did you take a backup on the older version? Your issues could be caused by restoring an incompatible backup.
The update from November to August included major version change of Kodi which also uses different database structures. For that the database is replicated during the upgrade process to a new version. So restoring a backup after the upgrade would not influence the running database.
Anyway upload debug logs as they would be the only thing that may bring some light to the problem.
To get a better understanding of the problem you are experiencing we need more information from you. The best way to get this information is for you to upload logs that demonstrate your problem. You can learn more about how to submit a useful support request here.
Depending on the used skin you have to set the settings-level to standard or higher, in summary:
enable debug logging at settings->system->logging
reboot the OSMC device twice(!)
reproduce the issue
upload the log set (all configs and logs!) either using the Log Uploader method within the My OSMC menu in the GUI or the ssh method invoking command grab-logs -A
publish the provided URL from the log set upload, here
Thanks for your understanding. We hope that we can help you get up and running again shortly.