we implemented for our Smart Home Skill both ways to link our account with user's Alexa Account,
(a) from the Alexa App, redirecting to our Identity Management
(b) App To App account linking
When the user performs (a) to link their account, and change the devices name, i.e. we trigger a proactive call to Alexa, to inform it, that the name changed. That works like a charm.
When we use another user, who linked its account via (b), we get an Unauthorized response from Alexa, although it's the same mechanism.
We suspect it's regarding permission, which are granted implicitly using (a) but not with (b).
Does anyone have an answer or an explanation?