iPhone phone call volume too low
I have an iPhone 11 Pro, just upgraded to IOS 17.0.2. The phone speaker is fine for music, ring tones etc but the volume is very low on phone calls (very hard to hear if there is any background noise). I have tried cleaning the speaker, toggling Bluetooth and Airplane mode and fiddling with the volume slider. Do not Disturb is off. I have also done a reset of all settings (a bit of a pain as I had to redo Apple Pay as a result). Any thoughts?