Does snapping not work for elements inside of a group/frame when there is a mask active? Why?

Problem: Elements inside a group do not snap when a mask is active.
I’ve included a gif of this behaviour.

Reproduce:

1. Create two elements.
2. Group the two elements.
3. Create a mask on the entire group.
4. Try to get them to align/snap. Doesn’t work.
5. Disable the mask.
6. Snapping works.

Sorry if this is a naive question, but why does this happen? Why can’t I find a single written article/post about this? Is this somehow supposed to be a feature?