Further testing seems to show that:
The “save” feature in the individual preset screen is definitely the cause. It works until I navigate elsewhere (such as simply selecting the algorithms page or simply closing and restarting the control app) and then the changes that were saved are lost. It seems the L-type presets get deleted and that even NON-H9 U-type presets are not preserved in the preset list.
FOR NON-H9 ALGOS: If I “copy to user presets” right after saving as described, a U-type preset is created. If I navigate about and come back (as described) the preset in the list is NOT the saved U-type preset. It is the prior one placed there (before modification and saving). However, it is easy to go into the individual preset screen and select the U-type preset from the left side of the screen; saving THAT preset in the list (WITHOUT MODIFICATION) is permanent. That seems to be the only way to attain permanence.
FOR H9 ALGOS: If I “copy to user presets” right after saving as described, a U-type preset is created. If I navigate about and come back, everything is fine … the modifications are remembered.
It’s hard to believe this bug exists at this point, but it does (at least on my computer).