There is no 'Fix'! I went through a long discussion with Ram Cares and my dealer trying to get this take care of.
Basically, it works as designed and Ram Cares told me that unless they get thousands of complaints, they won't even consider to change it. This is too bad as it really makes a few features of the truck to be too annoying to actually use on a daily basis as every time you go to use it, your ears are blasted bye the voice being much TOO LOUD!
It uses the same setting for navigation, text messages, speed alerts, etc.
If you get into the truck and while it's talking for the first time after turning on the radio, and turn the dial down to something that is reasonable. (if the windows are closed, 2 is about acceptable. If the windows are open perhaps a setting of 4 or 6 is ok), then it will stay that way until you shut off the truck and start it again sometime later (a varied delay is needed). If your volume level is above 15, it will remember your choice, but if you select any volume level below 15, it will default to 15 upon restart.
This appears to be a 'feature' to prevent people from turning their notification volume down to zero. and then missing voice announcements the next time the truck is used because the volume was at zero.
To fix this, it would require new software to allow the truck to keep the user's choice of a volume setting if the current volume is above 1, and then perhaps have an ON/OFF setting to allow the truck to reset it upon the next start. Or a "starting volume" setting, and let a user choose what volume they are comfortable with. No doubt, 15 is MUCH too loud!
I found this when trying to use the "Speed Limit Warning" feature where it would announce if you are going XX MPH over the current speed limit (per the Navigation system). Unfortunately it turned out to be MUCH too loud and was annoying! So my work around is to only announce the speed limit if I'm somehow exceeding 25 MPH over the speed limit (then I deserve to be loudly told about it).