Strange. I can even reproduce on different devices: Jolla C2 and even Jolla C (4.6), probably all of the other ones as well. If the ambience doesn’t explicitly set the ringtone volume to 0%, it disables mute if mute was enabled. It’s like it’s programmed to set the volume to the same level as before by default, but it forgets mute.
I also just noticed you don’t even need two ambiences, you can tap on the current ambience in the top menu and it’ll disable Silent mode if it was enabled.
This puzzled me as well a looong time ago, and took me even looooonger to find the culprit.
Using xplanet as background which creates every 10 min a new background pic and sets the ambience.
Hereby every time the silent mode was disabled. At that time I saw ringingrestorer as the bad one, but it was not (nevertheless led me find a small bug in it, correct it and which poetaster was so kind to take over).
But back to this here.
With your findings and a bit of testing myself again, it is good you created this bug report!
If you do not set a ring tone as action, silent mode and/or current loudness is not affected.
But as soon as a ringtone is set by ambience, loudness is set to default of 40%.
[Or, of course, to the specific loudness which you can set as another action of ambience - which would be intentional.]
So definitely a bug or bad implementation. Should be fixed!
