I noticed this in the past couple of days. Dunno if it's a change in the software, or a product of working more on my PCB but...
1. Create a PCB (Ha!)
2. Add traces for all wires of ratsnest.
3. Save PCB
4. Close
5. Open PCB.
Verify that some wires are back.
In my case, the fix is to "jiggle" the traces near the pad (mostly works), then hit UNDO (always works). This leads me to believe my traces are fine, but there's something in the software that's not.
Private schematic for now, but as admins, I can allow access to a clone of it, if it can help.