I also have tried many of the so called fixes that article mentioned. Nothing has helped at all.
Honda has no clue either. They actually told me to try the same things the article said to do.
I've pretty much given up. After a few minutes my cars display screen is lighting up like a Christmas tree,with the constant on/ off Bluetooth connection. The iPhone X does the same.
Unbelievable I spent $1k on a device that doesn't work with Bluetooth,and might have to buy one of those sun visor mounted Bluetooth units.
Apple really "F"d this up,big time. Can only hope the next version of 11 is better. The current version is a disaster.