Homekit hubs appear in multiple homes - with separate networks, making devices not reachable. (homepod minis)

I created two completely separate homes in homekit. Both homes are in different locations and don't share the same network. In each home I setup one homepod mini, which makes it a hub to remotely control the home as expected. However, after a short while, both homepod minis appear as hubs in both homekit homes, one with the status "connected" and one with the status "Standby".

This was irritating for me, as I would not have expected, that the homepod mini would get shared with the other home. In fact, I thought that this might be even an unintended security issue, given the fact, that I can invite other people to this home in homekit as well.

I couldn't find any way to "delete" / or "block" the homepod mini that is not physically present in one home, from becoming a home hub also registered in the second home.

However the real issue appeared, when the homepod mini of one location decided to not be the "Connected" one anymore, but changed without any clear indication why into "Standby" mode. With this status change I can't access the camera in the second location anymore and I noticed problems also with some Ikea Tradfri controller, that doesn't react to Scene control commands via Homekit anymore.

It seems, that the homepod minis / or maybe any kind of Apples Homehubs tie themselves via the iCloud account to other homes, even though with this they create issues.

I read, that some people found solutions by creating a separate iCloud account for each home and then invited the main iCloud account. However, this would also mean, that if you want to use for example Homekit Secure Video, you'd have to buy subscriptions for each account - if don't have a family shared account - on top of the fact, that this seems to be quite and unintended hassle.

Does anybody have a solution for this? Is this a bug? (- ... it seems at least to me.)

Thanks!