Using Bluetooth, does talking with one device means disconnection of another device?

I am getting very mixed results with multiple devices connected by bluetooth to my Samsung Note 20. The devices being 1. Samsung Watch 2. Honda - Android Play 3. Hearing Aids (any brand) If a call comes in, sometimes the Hearing Aids answers it, and other times the Car answers it. I found this post [How Many Devices Can Hook Up To One Bluetooth?](https://thegadgetbuyer.com/how-many-devices-can-hook-up-to-one-bluetooth/) >**Can You Connect Many Bluetooth Devices at the Same Time?**\ It is possible to connect many Bluetooth devices at the same time. However, only one device can be active at a time. Bluetooth connections happen in three distinct ways. 1. Is this true? 2. If only one device is active, are others disconnected at that moment? 3. Is there an authoritative reference for this? **EDIT:** When I picked my 4th pair of hearing aids to test, the Audiologist grabbed my phone and unpaired everything saying, that Android only works with 3 Bluetooth devices. Of course, I had to pair them back on. I have two headphones and a PC that also use Bluetooth. So do my bed and mattress. I am assuming that this action by the Audiologist is rooted in misinformation on posts such as the one above.