Can't change from Bluetooth to Speaker during Call

[The Fuzz 53]

I have a Pixel 2 and when I am at home, my phone connects to our Panasonic cordless phone base via bluetooth so that I can use our cordless phones to answer my cell phone. I run into a problem all the time where I answer the call via my Pixel 2, but the screen shows the sound source as Bluetooth and it will not allow me to change to phone or speaker, although the call is working through the Pixel 2. My father has the same setup I do and also runs into this problem. The only solution is to hang up the call and call back. Does anybody experience this? Is there another way to fix this?

 

[GSDer]

Not that it's a solution, but if you turn off Bluetooth (drag-down to access the Quick Tiles) temporarily the call should revert to your handset.