Ubuntu 22.04.1
Kernel 5.19.0-43
Steam Link 1.2.0.241 (also .240)
Sony PS4 DualShock controller (Bluetooth)

When using Bluetooth headphones, sound initially works fine with the Steam Link app; however, as soon as streaming begins it's redirected to the speakers.

After streaming finishes the sound reverts to coming through the Bluetooth headphones.