Maps' navigation instructions volume is too low in CarPlay, no way to increase it

I was finally able to reproduce this one that I've heard about before.

I had a rental car connected with CarPlay via iPhone tethered by USB-A-lightning cable.

In Maps navigation, was receiving on the road instructions for turns, etc.

But the volume was very very low. Simultaneously playing was music from another app, which was successfully paused while the announcement came on with a new direction.

I pulled over and tried to adjust it and try something, then drive again.

X volume on the car's radio just raises the entire volume including the music; the directions are still very soft

X toggled volume-button control in sound options so that the side buttons would increase/decrease the ringer and notifications volume instead of the general volume. didn't work.

X tried it the other way with the toggle, also didn't work.

Before I file a feedback on this (I have very little detail to go on), I wonder if anyone else has experienced this behavior?