In the thread How do I disable Background data, the impact of a bug is described.
Steps to reproduce
1. Have two SIM cards in your FP2, both enabled.
2. Go to the data usage monitor.
3. Click on an app entry - Result: You can restrict background data.
4. Disable one of your two SIM cards (preferably the one which isn't be used for data).
5. Go to the data usage monitor again.
6. Click on an app entry - Result: You cannot restrict background data anymore.
Do you also have this behaviour?
- Yes, I cannot restrict background data with one SIM card disabled
- No, I can restrict background data with one SIM card disabled
- I cannot test this
Edit: I'll move this to #software:bug-reports when there are at least 10 "Yes" voters or we have 5 more "Yes" voters than "No" voters.