My guess is that the original jensen was not Bluetooth and so you never had a microphone. The new one should have come with one that needed to be routed/installed somewhere. If the installer didn't put it in, you don't have a microphone. I would check with Jensen or your box to see if it had one, wherever you bought the radio, and/or the installer.
The specs on the unit say this:
Built-in Bluetoothยฎ with external microphone (A2DP/AVRCP/HFP/PBAP)
External microphone here is the key. If it wasn't installed, you don't have one. I poked around on Amazon and one user complained that their Microphone came unplugged and Jensen said it's a common problem.
Jeff - 2023 FR Sunseeker 2400B MBS