why is 'lots of ice cream' not correct?
It's also correct. Report it if it isn't yet accepted.
Should be- reported it
Seems to be accepted now (7 Jan 2021)
Would ' much ice cream ' also be okay?
It didn't accept it for me, but why?
"lots of ice cream" should be correct
Lots of ice cream is still not being accepted as a correct answer.
What's the difference between "paljon" and "moni"? Much and many?
"paljon jäätelöä" - lots of ice cream (mass noun)
"moni jäätelö", "monta jäätelöä" - many ice creams (countable)