microphone bar is changing the connected phone's song volume.

[Mustafa]

ive connected my computer with my iPhone 5s running lated ios12 and problem im facing is that ive connected the bluetooth of iPhone with ubuntu (just a direct connect not any thirdparty software ) and after connection when im playing a song on iphone it broadcasting it to ubuntu, the problem is that when i open drop down menu of Wifi/Bluetooth/Power menu from top right corner and change the microphone it changes the sound quantity and quality , but changing the volume bar changing volume of song in a manificient way rather than changing microphpone who is ruining the quality, and it is not supposed to change it :|

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: bluetooth (not installed)
ProcVersionSignature: Ubuntu 4.15.0-38.41-generic 4.15.18
Uname: Linux 4.15.0-38-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.4
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sat Oct 27 15:37:21 2018
InstallationDate: Installed on 2018-10-10 (16 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
InterestingModules: rfcomm bnep btusb bluetooth
MachineType: Dell Inc. Inspiron 3542
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-38-generic root=UUID=688940ab-691d-4fec-9fec-0f5d4c316bde ro quiet splash vt.handoff=1
SourcePackage: bluez
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/23/2018
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A14
dmi.board.name: 0DXYP6
dmi.board.vendor: Dell Inc.
dmi.board.version: A14
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: Not Specified
dmi.modalias: dmi:bvnDellInc.:bvrA14:bd05/23/2018:svnDellInc.:pnInspiron3542:pvrNotSpecified:rvnDellInc.:rn0DXYP6:rvrA14:cvnDellInc.:ct8:cvrNotSpecified:
dmi.product.name: Inspiron 3542
dmi.product.version: Not Specified
dmi.sys.vendor: Dell Inc.
hciconfig:
 hci0: Type: Primary Bus: USB
  BD Address: 9C:AD:97:15:3E:52 ACL MTU: 1022:8 SCO MTU: 183:5
  UP RUNNING PSCAN ISCAN
  RX bytes:22188568 acl:36355 sco:0 events:1564 errors:0
  TX bytes:51481 acl:454 sco:0 commands:341 errors:0