2 different accounts - same house

[schmuttis]

My husband and I have different Amazon accounts as are our devices (echo dots and 1 fire tablet).

I first added my account info/ and connected to my echo dot. HA showed 1 device 1 entity.

I added the credentials for my husband's account - email/pwd and restarted HA. HA then said it found one new device and asked for the 2FA which I generated and entered.

That never succeeded and I received error msg: "Config flow could not be loaded: 500 Internal Server Error Server got itself in trouble"

Now when I try to access my echo dot I get the same "Config flow could not be loaded: 500 Internal Server Error Server got itself in trouble" error.

What am I doing wrong? Is it not possible to connect to two different amazon accounts?