Prolific Academic - Orientation issues with Gorilla

GrannyKate

I have recently restarted doing these surveys after a long gap.  I am using an AppleMac (Desktop) - Three of the surveys which I have attempted today have got stuck at the beginning with a screen telling me to change orientation. Clicking the two options portrait and landscape on the page produced no effect.  No idea where to go from there - all surveys intended for desktop not a portable device and all three using Gorilla.  Can anyone more computer savvy advise please.