This has nothing to do with your page or item.
It appears to be an issue with many items and not just you. I myself have the same drop and so do many others (I regularly check the weekly top sellers).
I do not know why this is happening now but the drop is significant. Perhaps Envato changed something and if you haven’t been doing your own marketing then this could be a valid explanation.
Also the current world affairs (war) does not help and is a negative impact on consumer behavior. Consider that Gas, Petrol, Electricity, Grain etc are on the rise and many businesses are having a hard time coping if not shut down already.
I wish Envato would chime in to provide some more insight but they have ignored all threads with this exact subject matter. You are not the first to complain. Check link below: