So, I have discovered an unusual anomaly with Bluetooth today with my BraX3, relating to connectivity with multiple (identical) devices (not simultaneous obviously). It’s unclear to me if this is an iodéOS/LineageOS issue or a BraX3 hardware one, but my suspicion is the former due to replicating it on my Pixel 8 Pro? Apologies for long post but just wanted to clearly set the background and scenario.
I have 3 identical sets of (French) Focal XS Book Wireless bookcase speakers in my home (separate from my main Hi-Fi/HT system). These have a couple of analogue stereo cabled inputs (3.5mm and twin-RCA) but more importantly in this case they also a have a Qualcomm aptX Bluetooth module - ostensibly to provide them “HD” Bluetooth connectivity (i.e. near CD-quality). I’ve had these nearly 12 years, and the design/tech is 12½ years old now (~mid/late 2013 release).
When powered on they obviously all display the exact same name when you search for new devices to connect to, Focal XS Book Wireless, which isn’t an issue because when you connect to one it’ll sound a notification so you can tell which one you have connected to. Over the past 10 years or so I have had numerous iPhones, and couple of iPads, a couple of Samsung Android phones, several Windows laptops, and similar, plus the odd visitor with their random phone, all successfully identify these devices, incl. all 3 simultaneously, and be able to connect to any of them; and on my devices to save all 3 as devices for re-connection at later dates…
Obviously even though they all have identical display names their mac addresses are completely different. Also having worked in the Hi-Fi industry in the past I had a lot of experience with the French Focal range - fantastic products but there can occasionally be idiosyncrasies with their electronics, but up until now I have had no issues with connectivity of these particular units or this model.
On my BraX3 however it will only ‘see’ one of them to connect to - whether all 3 are powered on or not. It won’t even see the other 2, no matter what combination of things you do. In fact when I first tried to connect I had #1 powered on and #2 and #3 in standby - the BraX3 and iodéOS connected to “a” unit, but I couldn’t get any audio from #1 once connected, it didn’t make the connection chime sound and when I powered it off it didn’t ‘disconnect’ from the BraX3. So checking the mac address of the connected unit on my BraX3, it turned out it was speaker set #2 in a different room that was in standby (i.e. not powered on). So not sure how it even connected to that (but may be an anomaly of the Focal devices as alluded to above).
Regardless, deleting the device and powering all 3 on, and searching for them and reconnecting always returns that same result - it finds and connects to #2 and never even sees the other active devices (#1 and #3).
I have replicated this exact same behaviour on my Google Pixel 8 Pro running iodéOS also. Both BraX3 and GP8P are running v7.2.
I also tried disabling the Qualcomm aptX but that’s only possible once connected on the phone, so doesn’t seem to help with finding and connecting to the other devices (its referenced elsewhere as helping with no audio from headphones issue in Bluetooth aptX Codec causes problems post).
My suspicion is it possibly doesn’t like the fact the device display names are the same, even though all 3 mac addresses are unique, and hence thinks they are all the same device. …and I think the unit it connects to has the ‘lowest’ alpha-numeric mac by the look of things; so that may be why it’s always showing and selecting that specific device of the 3. But ultimately I think there is a bug of some-sort with the Bluetooth stack / device identification in the OS, especially as it identified and connected to a device in standby mode (i.e. not actively on) and ignored one that was on, AND then won’t even identify the other 2 identical devices at all.
@vince31fr & @rik just tagging you as FYI.