Using the number pad on a keyboard when running MuseScore4 on a PC

I recently downloaded MuseScore4 and transferred my MuseScore 3.6.2 files to the new version. I am now in the process of entering music into my previously generated projects. I am finding that I can't use the number pad on my keyboard to set up note durations. The numbers "row" on the main keyboard works correctly. I see no hints in the online manual to tell me how to activate the number pad.