Import from a remoted database > Import Presets
You would need to create a preset, save it, update it
Create some new ones
Create some based on the old ones (Save current preset as) and update those (maybe with similar names)
Hopefully you will already see issues with names that are appearing equal. If you then delete one of those, I hope you see that the wrong ones get deleted.
This is a very difficult problem to explain, and I understand to solve as it isn't easy to recreate the problem.