Items not showing on 'Find my' iCloud version

I have an iPhone and non-Apple laptop. On Find my... on the iPhone I have paired 3 items (Spotminder trackers) in addition to my iPhone (device). But when I go into Find my... via the laptop (on iCloud), only the device i.e. the phone, shows up. This isn't very helpful as it means if I've mislaid an item and don't have access to my phone (maybe as it's in the same place) I cannot use the laptop to find it?

Why can the iCloud version not show items which are clearly already linked to my Apple account?