MIDI variables disappear after restart

[Zydnar]

Steps to reproduce:
1.

2.

3.

4. Enable plugin and restart project

5. a) Create somwhere let's say in ThirdPersonCharacter blueprint variables or add components from MIDI plugin

5. b) Save and restart
6. a) Open project one more time and you see this while opening editor:

6. b) and this while opening blueprint containing MIDI components or variables. Everything is gone:

Reproduced multiple times on different PCs and on different engine versions supporting the plugin. I tried this https://answers.unrealengine.com/questions/770929/unreal-cant-find-my-player-blueprint-assets-please.html but it didn't help.

[Zydnar]

For some reson bug does not exist if I skip getting devices and instead use Midi Intercace