Shows the latest user-defined Direct X plugin, not preconfigured Direct X plugin.

I selected "Master for 16-bit" and when I opened it again it appeared as it is in the image.

Are you opening Wave Hammer as a single plug-in or in a chain? If in a chain, is it the timeline FX chain or the destructive "Apply Plug-in Chain" in Favorites?
When I launch WH or other DX plugs, it shows the last used preset.

Where is "Master for 16-bit", is that somewhere in 'Instant Actions'.

Effects tab, Wave Hammer. Single plugin. When i close SF and open it again, show "Preset Untitled" instead "Master for 16-bit".

SFP-15 does not exhibit that behavior. on my PC.. SFP-16 does though, which should be fixed in the next update. I do not recall that behavior with any build of SFP-15 and I would have certainly noticed.. Some of my 'go-to' plug-ins are DX .
Try a reset, or uninstall-reinstall if reset does not fix it.

I reset and reinstalled. The Preset name sometimes appears and sometimes it does not. But that's not a big problem. Thanks for trying to help.

When I click OK, the Preset name keeps showing. But when I close the window without clicking OK, it shows Preset Untitled. Watch the video:

I reset and reinstalled. The Preset name sometimes appears and sometimes it does not. But that's not a big problem. Thanks for trying to help.

I had this problem with my preset chains in SFPro15. Like you, it was intermittent and seemed to happen at random. Not a big problem here as well, although it could get cumbersome having to check the parameters of the chain to see what preset was used last.

I hope Support will check the issue and fix it.

@john_barr

Since I think you are using SF Pro 15 and, as you know, SF Pro 16 has now been released, I think it very unlikely that any changes will be made to the earlier version.

Jeff