Anyone else noticed that sales rank is not updating on sales?

I’m not sure if it’s just me but as I’m going through my inventory to delete items I’ve noticed that sales ranks have not been updating.

Normally after a sale within a few days sales the product gets assigned a sales rank which is displayed.

Some of the items in my inventory have no sales ranks even though I know I have sold items over the last few weeks so it should have a value even if it’s a lower one.

Also products which have a sales rank do not appear to be increasing even after sales have been made.

This seems to be reflected in search results. normally a sale will boost a product but that does not seem to be happening.