Audio settings not visible in Kubuntu (disappeared); can't listen & speak

Question

Following are the sequence of events which has happened to my laptop recently.

Event 1:

I logged into Kubuntu as usual, but I saw that volume control is crossed out in the taskbar. When I clicked on that, I saw that I can only control the audio input (mic) volume. The output slider was not there to control.

Event 2:

I followed some of the troubleshooting method on the internet which removed pulseaudio and then reinstalling it. I did it, but it didn't restore the sound output. In return, it removed the audio settings in the setting center.

Please suggest something as with my current setup, I won't be even able to attend meetings.

Edit 1

I just noticed that I can change the volume from pavucontrol and it works.

But I still don't see any controls on my taskbar. Also, my volume shortcut on my keyboard does not work.

Edit 2

The audio input also works the same way as described in Edit 1. But I can't see the normal controls.

Edit 3

It seems like I have lost both output and input again after a restart.

Answer 1

Okay, so here I'm going to answer my own question. But let's first know how I got into this situation.

My entire problem can be divided into two parts:

Part 1: Audio input/output not coming

Why

After a lot of investigation, I found out that pulseaudio daemon was not starting when system started.

How I got into this situation

I don't exactly remember why, but I installed pipewire a few days back.

Fix

I uninstalled pipewire. Also make sure pulseaudio daemon is starting at system boot.

But I read somewhere on the internet that both the packages can co-exist if we configure properly.

Part 2: Audio controls not showing

How I got into this situation

While trying to solve the first problem, I uninstalled plasma-pa package which is responsible for showing icon on the taskbar as well as the system settings.

Fix

Install plasma-pa.