Android forgetting default launcher every few minutes
It's still unclear what is causing this to happen and I have found only one other mention of the problem so far. In the end I simply disabled the stock launcher by freezing it using Titanium Backup and also disabled all other custom launchers. Soon as only one launcher is available, the dialog goes away. More of a workaround then a solution, so if anyone has an idea how to continue debugging, then I'm open to any suggestion.