Regression: Carla instruments do not save/load properly; sound completely different after reload

Bug Summary

When loading a project file with Carla instruments on Linux, they sound completely different and have many of their parameters scrambled/changed resulting in an entirely different sound.

Steps to reproduce

1. Make a new project file
2. Add a Carla track.
3. Open carla and load Vital (I've been using the linux VST2 version, vital.so)
4. Pick a preset of your choice and play some notes.
5. Save the project file and close LMMS.
6. Reload the project file.
7. The Vital instrument will now sound completely different. Opening the plugin interface will show that effects have been toggled on/off, parameters are wrong, etc.

Expected behavior

Plugins sound the same before and after saving.

Actual behavior

Plugins sound very different and have drastically changed settings.

Screenshot

• Vital just after loading a preset (looking at the Effects tab where the issue is most noticeable):
  

• Vital after reloading the project file (looking at the Effects tab where the issue is most noticeable):
  

Affected LMMS versions

Currently using version 1.3.0-alpha.1.512+g8e8f68552. I don't have specific versions that I know worked pre-bug but I get the sense that #5846 may be related -- I know my previous version that worked was prior to this commit, and I've had no luck with versions post-commit.

Reproduce on Linux with a Carla track hosting the Vital VST2 plugin, then save and reload the project while comparing its parameters and sound. Trace the Carla instrument project save/load path and verify completion by confirming that effects, parameters, and sound remain unchanged after reopening the saved project.