‘Manage inventory’ item image not showing up?

I created a new listing today with variations, and it appears that the listing images are all ok (all the pictures show up when I open the listing).

However, on my ‘Manage inventory’ page where it shows all my listings and a mini image of the listing images, it is showing ‘no image’.

I have tried to upload new images to the parent ASIN, as well as upload new photos to the child ASIN but still no luck.

Any idea how to fix this?

TIA