I can confirm that a similar behaviour also exists with my Helix LT on Windows 10 & 11.
I am up to date with the firmware 3.61 and HX Edit 3.61.
It is totally random when this happens but it does happen reguarly and noticed it was happening before the last 3.5 & 3.61 updates.
I do reboot the Helix after making changes so that it can rebuild its presets before I make a backup of a preset.
With me the problem (BUG) is:
1. copying or dragging presets from on preset location to another within HX Edit = various settings i.e. noise gate settings, delay settings, cab settings, volume settings etc... randomly change for the worse on various snapshots within that same preset.
2. Importing a preset from PC to another preset location on the Helix = various settings i.e. noise gate settings, delay settings, cab settings, volume settings etc... randomly change for the worse on various snapshots within that same preset.
I open the files with Notepad++ and do a compare between two copies and can see that random settings have been changed just by exporting the file from HX Edit.
I change the settings back to how they should be in Notepad++ and then re-import them back into Helix. BUT the settings have changed back for the worse again and all the corrections are gone on that preset.
I am doing all of this from within HX Edit 3.61. I am currently running Windows 11 & have disabled my antivirus on the PC just in case.
The only way to fix this for me is to go through all the blocks and see where the settings have been changed and make the ammendments again & resave.
If I then try to export the file or move it to another preset location it changes the settings during the copying process again for the worse.
The original preset in its original location remains intact.
This behaviour seems to randomly happen only when moving or backing up/importing a preset. :(