Nothing like a Monday morning challenge to get the week started
You're right that there are many potential contributing factors to the "flubbing"...
Did it occur suddenly or was it the difference from one game to another?
I would recommend that you start by looking into the most common contributory factors:
- Battery (replace with a known quality Alkaline 9 volt battery)
- Check that your OOPS insert is tight
- Check that your OOPS knob is secure and depresses the pin in the insert properly.
Please let us know how you get on with the above.