The oxygen bar is refilled when you consume some oxygen and get water breathing effect

This does not occur in 1.21.3 and 24w46a.

Steps to reproduce:

1. Go to the underwater in survival mode and wait until empty state of air bubble icon appears
2. Run /effect give @p water_breathing 10

Expected result: The oxygen bar stops decreasing and retains its state.

Observed result: The oxygen is regenerated immediately.