Content added dynamically
To check if the content is added dynamically, using Chrome,
Open the URL of the source data.
(maybe not the answer, but here is a quick humble scraping guide)
the first choice is always IMPORTHTML and slowly (1-by-1 row) dragged down
=IMPORTHTML("URL"; "TABLE"; ROW(A1)-1)
if that fails then repeat it with:
=IMPORTHTML("URL"; "LIST"; ROW(A1)-1)