No sound when completing a Todoist task

Steps to reproduce:

1. In Todoist General settings, ensure the "Task complete tone" is enabled under Sound & appearance.
2. Complete a task in Todoist by clicking the unchecked-checkbox for the task in the task list.
3. Hear no "task completed" sound.

Compatibility mode has no effect. Safari will play the tone correctly.

Expected behavior:
A sound should play when the task is completed.

Orion, OS version; hardware type:
Orion Version 0.99.115.3-beta (WebKit 614.1.12)
Big Sur 11.6.7
Mid-2013 MacBook Air