Hi Julia,
Thanks very much for investigating, and even sending screenshots to demonstrate that it’s working…
Well as I said, I tried using the system with Firefox on 2 different computers and it didn’t work, but now I realized that there was one thing the same on both copies of Firefox – they were both using the AdBlock addon… now I tried turning off AdBlock and sure enough the system works absolutely fine. I never suspected that AdBlock could be the problem because it usually only blocks images, I’ve never seen it stop a dropdown menu from working…
So the problem is solved. And the problem was on my end, sorry about that :rolleyes: At least now you can inform anyone else with this problem in the future 
Now I’ll duck for cover before any anti-AdBlock webmasters come after me 
Thanks again Julia.