[WIP] [BUGFIX release] SortableMixin properties can't be set with setProperties. 

SortableMixin doesn't currently work if `sortAscending` and `sortProperties` are set at the same time using `setProperties`.

Failing tests copied from or based off of: #3422

- [x] Failing testcases.
- [ ] Working solution.

Notes:
- Tagged as release, but not urgent as there are simple workarounds.
- Closes #3422.