You can keep the presets that the Preset Sync has downloaded for you and have the Preset Sync uninstalled. But, this will mean that the presets uploaded to the sync will not show up for you unless you periodically install the preset sync to stay updated with the latest presets that are uploaded.
However, before we try any of that, I think it would be wise to do a full reinstall of the game. Backup all of your custom content to a different location and then completely erase your FeralHeart folder. Then, install a brand new copy of the game, first without the Preset Sync and see if the problem is fixed. If it is, install the Preset Sync and see if that is the issue.