Bug Spawner Block Subgraph isn't saved.

Hi, guys from Unity Tech!
Here is my problem.
I've created Subgraph Block to use it in Spawn Context. Everything was fine, but every time project is reloaded, "Suitable Contexts" field resets and I have to manually change it to "Spawner" and fix graphs that depend on it. Then, everything is fine until next project reload.

It is a really annoying bug and hope will be fixed
Thank you in advance!