Ah, I’ve just found it. If you drag and drop and save then all is good but if whilst you are still in drag and drop mode and then double click on any preset to try and view it from that list it deletes the preset to its right. Is that to be expected? That’s a glitch no?
That’s how it works. You are in Drag & Drop mode, so you cannot double click on a preset to edit it. The first time you click you select it. The second time you click it, you are supposed to drop it somewhere. If you release the mouse quickly and drop it no where, you are deleting this preset and all following presets move back 1 slot. If you’d like to keep that prest there, you can either:
1) Cancel your change by clicking “Back” and not saving.
2) Drop the preset on the left edge of the slot to put it back to its slot before releasing your mouse click.