Marketplace on switch not loading or syncing, crashing on iPad

Hi! My sons account seems to have a bug. On his iPad every time he opens the marketplace the app crashes. On his Nintendo switch account the marketplace won't load, it just says it's not available or to check the internet (which is fine) and it is not syncing all his past purchases. They were all purchased with his Microsoft Xbox live account so all purchases are saved through there.  However if I log into his xbox account under my Nintendo switch account the marketplace will load but it is still not syncing previous purchases and I can not figure out how to restore or sync his purchases. Please help us get his game (the switch was his main Christmas present) up and running properly, thanks!!