Problems with OpenType and Classes v.3.0.3

I’m experiencing a couple of problems with OpenType code and classes in Glyphs 3. I’m working on a font that I started in Glyphs 2 and brought over to Glyphs 3. I don’t know if the problems could be related to that.
Here’s part of the code:
lookup s.ss01 { # Alternate s
ignore sub s' [s r.ss01];
sub s' by s.alt1;
} s.ss01;
When the feature is active in the edit view, the default ‘s’ is shown instead of ‘s.alt1’ as it should. It worked fine in G2 and I can still generate the font and it works fine in Adobe apps.
Also The first class in the classes list is always blanked out (all glyphs erased) when Glyphs is quit and reopened. It doesn’t matter which class it is. I deleted and recreated the top class and moved it to the bottom of the list. When I quit and reopen Glyphs the class that is now at the top is empty.
Thanks, I’m otherwise really enjoying Glyphs 3!

Can you send me a screenshot of that first class and the saved file?