I've done hundreds of upgrades. That is not normal.
The only time I have ever seen that is if I exported a workflow then reimported it with the same name. Is it possible someone imported an EPDM export file with your workflows..twice? Maybe even before you did the upgrade?
Do some searches...I half way guess there aren't any files in these new workflows. If there are, check when the files were added, that may give you a clue of when those workflows were created.
Ensure your backups are up-to-date, if those workflows are empty you should be able to delete them.
Pretty weird. Watch the vault closely for a while.
I had this happen too only one copy and it was a pain to remove. I figured out it was from when I created the vault I used a .CEX file to make everything. Then because it missed things I did an import of the same CEX to get the missing data. It gave me a second set of workflows. The import did not duplicate anything else and when Importing I did select to overwrite existing files. I think I would have been better off starting form an empty vault and then importing rather than trying to import one over the install.
Did you do multiple imports like I did?
Yes, this was the solution. I mistakenly exported everything out to a .cex file and then imported into my new vault. I did not realise that all of the vault settings had been restored with the databases and vault data. I went through the entire procedure again and did NOT import the .cex file I had created and this time no duplicates.
AFAIK, I too encountered the same when we upgraded at a customer's place. Found out that there was a BUG reported. Dont have the SPR number handy, You can check with the reseller or the knowledge base.
There is an Hotfix available for this too. After the hotfix the workflows will display correctly.
Hope this helps !