“Handset” volume too low and not adjustable

When I answer a call using “Handset” mode I cannot hear the caller nor can I adjust the volume. This was not a gradual decline. One day it worked fine, the next day I could hear nothing.

”Speaker” and “Bluetooth” both work perfectly fine.

I despise using the “Speakerphone” mode and it’s a hassle to have to pull my earbuds out of my pocket to simply have a private conversation.

I have “cleaned” the handset speaker.

Any suggestions?

iPhone 11 Pro Max

iOS 18.1.1