I know that the Notification Diagnostics feature in eBay app > Settings
> Notifications should have detected that you had the selling channel
marked as silent, but wouldn't tell you if the sound was changed to
something else. Glad you figured it out ...
You should be able to use the do not disturb feature on your phone and
set it for certain times:
https://support.google.com/android/answer/9069335?hl=en#zippy=%2Cset-how-long-do-not-disturb-lasts%2Cat-certain-times
