Sound input is not automatically switched back from headphones mic to internal microphone

[Andycds]

When plugging in headphones, sound input is correctly switched from internal microphone to the headphones mic. When the headphones are unplugged, sound input is NOT automatically switched back to the internal microphone.

Sound output is switched back and forth correctly.

This bug started happening on my system after I upgraded from 19.10 to 20.04 so it is a regression. Attached is pulseaudio log of what happens when I plug and unplug my headphones.
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: anderson 2247 F.... pulseaudio
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2019-08-24 (263 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
Package: pulseaudio 1:13.99.1-1ubuntu3.2
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
Tags: focal
Uname: Linux 5.4.0-29-generic x86_64
UpgradeStatus: Upgraded to focal on 2020-04-25 (17 days ago)
UserGroups: adm cdrom dip docker lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 01/06/2020
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.10.0
dmi.board.name: 0W83FH
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.10.0:bd01/06/2020:svnDellInc.:pnInspiron7580:pvr:rvnDellInc.:rn0W83FH:rvrA01:cvnDellInc.:ct10:cvr:
dmi.product.family: Inspiron
dmi.product.name: Inspiron 7580
dmi.product.sku: 08A6
dmi.sys.vendor: Dell Inc.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1878312/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:

  apport-collect 1878312

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Andycds (andycds)]

apport information

[Andycds (andycds)]

apport information

[Andycds (andycds)]

apport information

[Andycds (andycds)]

apport information

[Andycds (andycds)]

apport information

[Andycds (andycds)]

apport information

[Hui Wang (hui.wang)]

This is a duplicate bug of this one：　https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1876065

[Hui Wang (hui.wang)]

Please use the testing ppa in the #1876065 and verify if it could fix the problem.