I've gotten exactly this issue in PipeWire (https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/2468 https://gitlab.freedesktop.org/pipewire/pipewire/-/is

I've gotten exactly this issue in PipeWire (https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/2468 https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/24...), where it would accidentally start playing audio before it starts writing it, then write one more block of audio the moment the first block was fully depleted, and so on until the delay-locked loop gradually pulls PipeWire back into normal operation. The intended operation was that 1 block of audio was compute and written, then audio playback was started and a second block of audio was immediately computed and written, afterwards waiting for the first block to finish playing before generating a third block. Note that this PipeWire bug has been "fixed" (still behaves oddly in some cases last time I tested, don't know its current status).