Nintendo Switch Log-on issue

When trying to log-on to my Minecraft account on Nintendo Switch, nothing seems to happen - just a black screen for several minutes until it says "sorry error has occured" and then kicks me off back to home menu screen on Switch. 

On the rare occasion when I can log-on, all of my previous purchases are unavailable. 

The game works when I open it with other accounts on my switch, just not with the one linked to Nintendo switch online and the Minecraft account. I have tried uninstalling the game and then reinstalling it... I even tried a complete wipe of the console memory and starting up from scratch again. Still nothing.

Really disappointed as had spent a good deal of money in the minecraft store and now have no way of using my purchases.