iWatch Built-in apps not downloading/installing after reset

Hi, I've received my first iWatch yesterday. I managed to link the watch with my iPhone SE 2020 and the watch is configured. I notice that most of the built-in apps are unavailable. Their icons remain black-ish with a lighter colour ring around it. When I click one, after a while I get the message that the 'app cannot be downloaded at this time, try again later.'

Strange thing is that the custom apps, such as spotify and evernote are downloaded and work just fine. I've unpaired watch/phone twice already to no avail. Also enforcing to let the watch use wifi instead of BT by putting the phone in airplane mode does not help. What can I do to get things rolling?