I have the very same issue. Refurbished Macbook Air M1. Got it yesterday. Set up a new computer.
I can download Mac apps but none of the ipad or iphone apps displayed under iphone+ipad apps tab I purchased:
I click on the "cloud-arrow down" symbol nothing happens.
If I click on the name of the iphone/ipad app I see the details. If I click the cloud symbol there I see the circle swoosh for 2 seconds and then it is back to the clow symbol.
I am in conversation with Apple support. Had been talking to three different people. No one so far that could help
This is rather frustrating.