Rules not showing in style active panel if there are empty

I didn’t have this error with Pinegrow 4. I don’t know if it’s a bug or it’s something I’m doing wrong.

  1. I create a rule with an element selected.
  2. This rule don’t show in style active panel.
  3. I can see in the stylesheet file, so it’s is created.
  4. I insert some property in the rule (in style/file.css panel).
  5. I go back to active panel.
  6. The rule now is present!

Only happens with LESS and SASS files. Plain CSS works ok.

Thanks

Pinegrow 5.0 (5.0)
macOS Mojave 10.14.1 (18B75)