MacBook Pro ongoing issue with connected bluetooth speaker, no sound

I've traced most of my Bluetooth issue to interference in or around a workstation:

Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

Example: at home, my BT mice and keyboards seldom had an issue. At a museum where I volunteer I had many BT disconnects with the very same computers and accessories.

The museum's volunteer desk is Ground Zero for all the facility's tech. Due to accessibility issues, everything is ON the desk, not under, above, or behind†. Router/modem, base station for our wireless phones, a credit card reader, a Win computer, and a wifi-enabled multifunction printer. Looked like a techie's rummage sale!

Simply moving the printer 40 feet to the museum director's office virtually eliminated my Bluetooth disconnects that I was having with my gear when volunteering.

† — at home, our wifi and BT devices are on three distinct levels. Computers (3), mice and keyboards so on the middle desk-high level. Router/modem, one wifi printer, and all the networking hubs are basically at floor level. A second wifi printer is above the level of the computers and horizontally about halfway between my workstation and my wife's. So maybe spacing helps.

APPcoLE wrote:

For the last few major versions of macOS (since Ventura, maybe), my MacBook struggles (or completely fails, at times) to play audio through a connected (and selected) Bluetooth speaker.

To summarize: WHY?

My specific MacBook and speaker model don't seem to be important, considering the wide variety of Macs and speakers experiencing the same problem on reddit - 2019 MacBook Pro 16" and earfun UBOOM L

By comparison I have had no issues with bluetooth speakers on my 2019 MacBook Pro 16 going way back past your Ventura for reference;

what does seems to be important is this your issue has carried over through four operating systems...

So either it is

—the exact and particular speakers (?)

—or you have some conflicting third party software

—or you have a hardware issue

ref: User Diagnostics to test your Mac for hardware issues

Use Apple Diagnostics to test your Mac - Apple Support

ref: get a good look at your User/System config. and reveal conflicts or issues w/ third party software

https://etrecheck.com/en/index.html

(If you need help interpreting the report you can post it here in its entirety in the "Additional Text" box in the editing toolbar below, in your reply. )

The current stable release of Tahoe including bug fixes, security updates is macOS 26.0.1

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support

no insight or resolve—

To be proactive you can file a bug report / submit your Apple Feedback here: Product Feedback - Apple