Bluetooth Outgoing Calls Are Inoperative

[Paul M]

I have a Lexus ES 300h and an iPhone 6.  Bluetooth was working appropriately.  Intermittently outgoing calls would transmit but would not be heard via the Lexus speaker system but could be heard on the iPhone speaker or handset.  Incoming calls worked fine.  My dealer deleted the bluetooth settings on both iPhone and Car but the problem would still reappear intermittently.  The same problem existed when another iPhone/Android would be connected to the system, so Tech Support concluded the problem was not the phone.  They replaced the radio since the chip for bluetooth was a non-replaceable component of the radio motherboard.  The bluetooth functioned correctly for 1 1/2 days and the intermittent problem reappeared.  The car is going back into service.  Has anyone had a similar problem and what was the fix?