Sounds when muted/silent

How do you mute it? If you use a Silent Ambience for the purpose, does the Ambience by chance have a sound/tone selected for the Chat option by accident? I would guess both apps use the Chat sound, so it's possible it's active from somewhere where it shouldn't.

I'm not exactly sure how the device main Sounds settings under Settings - Sounds and Ambience custom sound settings override each other nowadays, but back in the day I had hassle from Ambience Email tone overriding my main "no tone" Email setting from Settings - Sounds.

I don't switch ambiences. I just set the volume slider to 0% from sound settings. So it should be the "master volume" and it should override any other settings.

Technically that's the "Ringtone Volume". There is another slightly hidden volume setting, "Volume", that you get to by pressing the device's physical volume buttons while having an (Android or some of the native) app open.

My Sailbook app sounds seem to be controlled by the "Volume" rather than "Ringtone Volume". At least the videos are, I can't confirm the Chat sound, but you should try silencing the Sailbook/Sailorgram apps from physical volume buttons whilst in the app and see what it does.

Pressing physical buttons while in Jolla apps like Weather, Calculator and some other native apps show and adjust the "Ringtone Volume" bar. Android apps show and adjust "Volume". It's possible that Sailbook and Sailorgram have for some reason been programmed to use the "Volume" which keeps the Chat sound audible when not set at 0 while "Ringtone Volume" set at 0 mutes ringtones etc. at the same time.

So, as the answer to the question of who is the culprit for the problem: it possibly is the third-party app that uses "wrong" volume setting for the app (insofar as/if the native apps are supposed to use the "Ringtone Volume" instead of "Volume".

But we can also blame Jolla a bit for making this two-sound-settings thing so confusing. Chances are you will only learn of it's existence first time if you adjust "Volume" from the buttons while in an app, and immediately close the app while the Volume bar is showing, at which time it will change into Ringtone Volume bar and the balk visibly adjusting because of different sound level in the two settings home you into a "What the hell was that!?" moment and realization.

Before that you may succeed in embarrassing yourself publicly by the phone blarting out moment-inappropriate sounds with full "Volume" while you (correctly) thought you had set "Ringtone Volume" at 0.

There is btw also a top-pulley "Mute" option you can add to Lockscreen from Settings - Lockscreen for handy muting purposes, but I'm not sure if that mutes both "Ringtone Volume" and "Volume" or only the former.

Well, damn: I tried doing stuff to see what happens, and all of the sudden my Sailbook adjusts "Ringtone Volume" instead of "Volume" like it did on my previously reported comment. There seems to be something wonky that makes the app switch from the physical buttons adjusting one sound setting instead of other. I don't know if playing a specific kind of video or other content (and evoking specific libraries for it) in Sailbook might be the cause to switch the Sailbook app to control volume setting B instead of volume setting A. But this might go to explain why a reboot fixes it as the app will again work correctly.

edit: oh, yes! I reboot the device and open up Sailbook, the device volume buttons control "Ringtone Volume", but when I watch a Youtube video on the Sailbook app, the buttons bring up and adjust the "Volume" instead, and once I have exited the video back to the normal FB wall view, the device volume buttons keep controlling "Volume" and not "Ringtone Volume".

I close the Sailbook app and open it again, the device buttons once again control "Ringtone Volume".

My app was old version, 6.4-0, but also the newest one 8.9 does the same thing.

So, doing certain actions in the app may somehow switch the Sailbook app to use the other volume setting "Volume", and if the Chat sound also starts at this point to be controlled by "Volume" instead of "Ringtone Volume", then muting "Ringtone Volume" won't mute it like it does with the other Sailfish sounds.