How do I stop AirPods from linking to another Family Sharing account?

Every once in a while, my AirPods will suddenly get linked to my wife's Apple ID in addition to my own. This means her phone may start playing audio through the AirPods while I'm listening to something from my own phone because of automatic device switching.

• We have 2 different Apple Accounts that are part of Family Sharing
• We have 1 computer in the household, but have 2 different accounts on the machine, each signed in with our respective Apple accounts.
  • I suspect this is what's creating the problem somehow, even though the AirPods are supposed to only be linked to one Apple Account
• We each have an iPhone, each with our own Apple Accounts used. There is no account sharing whatsoever.
• All devices are completely up to date with the latest OSes
• This seems to have been happening ever since the September 2024 releases (iOS 18, macOS 15)
• I have tried (on several occasions) forgetting the Airpods from both our accounts, but it quickly comes back.

Does anyone know how to prevent the AirPods from becoming associated with her account? The only workaround I've found is to turn off the automatic device connection on her devices, but this still feels like a security vulnerability waiting to be exploited

[Re-Titled by Moderator]