The key to all this is to regularly do a forget all devices and discover devices with Alexa.
Alexa will eventually discover newly added devices however since the corner stone to everything is the HA-Bridge there is a reason to forget devices. Device IDs can get changed with any adds/deletes or even Bridge resets.
I'm told Alexa looks at the IDs first and if a name is assigned it already it ignores the name.
When it does this it is possible she'll tell the bridge to switch state of the wrong device since she sends the bridge the device ID not name.
The way to remedy this is to forget devices then rediscover anytime you delete/add a device but especially true if you reset the bridge.
I'd also do this with an Alex10 update that includes a new bridge.