I am running a study online (Prolific). A participant shows up in my data (and monitor) but the "Page Name" column is blank, and the "app name" and "round" columns are also blank. "Progress" column shows they are in the first page, but the page name is blank. 
I have never seen this before, any ideas why this could happen or how to interpret? They also don't show up on the prolific platform.

Could you please paste a copy of your init function and html pages?