pavucontrol is not switching to headphones in Ubuntu 18.04

Question

It is a strange problem in my Ubuntu 18.04 OS. The OS is not detecting my headphones, as if the headphone jack is broken/faulty. The output tab in the sound window is not changing, even if I plug or unplug my headphones, as shown in a screenshot below:

After searching the internet and installing pavucontrol, I found that pavucontrol also shows "Headphones (unplugged)". Strangely, selecting "Headphones (unplugged)" from the dropdown menu makes sound in my headphone. Please see a screenshot below:

However, plugging and unplugging the headphone is not detected. I tried many suggestions but have yet to be successful so far. Below is the other information:

$ inxi -SMA
System:    Host: ravi-laptop Kernel: 5.4.0-137-generic x86_64 bits: 64 Desktop: Gnome 3.28.4
           Distro: Ubuntu 18.04.6 LTS
Machine:   Device: laptop System: Razer product: Blade v: 1.04 serial: N/A
           Mobo: Razer model: DANA_MB serial: N/A UEFI: Razer v: 01.01 date: 08/31/2018
Audio:     Card-1 Intel Cannon Lake PCH cAVS driver: snd_hda_intel
           Card-2 NVIDIA GP106 High Def. Audio Controller driver: snd_hda_intel
           Sound: Advanced Linux Sound Architecture v: k5.4.0-137-generic

The alsa force-reload command does not return even after a few minutes. So I have to press Ctrl+C. See the output below, please:

$ sudo alsa force-reload
Terminating processes: 2012 10053
10053 10347
10347 10774
10774 (with SIGKILL:) 11413
11413 (failed: processes still using sound devices: 12091(pulseaudio)).
/sbin/alsa: Warning: Processes using sound devices: 12091(pulseaudio). 
Unloading ALSA sound driver modules: snd-hda-codec-hdmi snd-sof-pci snd-sof-intel-hda-common snd-soc-hdac-hda snd-sof-intel-hda snd-sof-intel-byt snd-sof-intel-ipc snd-sof snd-hda-codec-realtek snd-sof-xtensa-dsp snd-hda-ext-core snd-hda-codec-generic snd-soc-acpi-intel-match snd-soc-acpi snd-soc-core snd-compress snd-pcm-dmaengine snd-hda-intel snd-intel-dspcfg snd-hda-codec snd-hda-core snd-hwdep snd-pcm snd-seq-midi snd-seq-midi-event snd-rawmidi snd-seq snd-seq-device snd-timer (failed: modules still loaded: snd-hda-codec-hdmi snd-hda-codec-realtek snd-hda-codec-generic snd-soc-core snd-compress snd-pcm-dmaengine snd-hda-intel snd-intel-dspcfg snd-hda-codec snd-hda-core snd-hwdep snd-pcm snd-timer).
Loading ALSA sound driver modules: snd-hda-codec-hdmi snd-sof-pci snd-sof-intel-hda-common snd-soc-hdac-hda snd-sof-intel-hda snd-sof-intel-byt snd-sof-intel-ipc snd-sof snd-hda-codec-realtek snd-sof-xtensa-dsp snd-hda-ext-core snd-hda-codec-generic snd-soc-acpi-intel-match snd-soc-acpi snd-soc-core snd-compress snd-pcm-dmaengine snd-hda-intel snd-intel-dspcfg snd-hda-codec snd-hda-core snd-hwdep snd-pcm snd-seq-midi snd-seq-midi-event snd-rawmidi snd-seq snd-seq-device snd-timer

The systemctl disable timidity doesn't help either as shown below:

$ systemctl disable timidity
Failed to disable unit: Unit file timidity.service does not exist.

I also tried reinstalling alsa and pulseaudio packages but no success. Further the alsactl restore command did not work either.

$ alsactl restore
alsactl: state_lock:125: file /var/lib/alsa/asound.state lock error: File exists
alsactl: load_state:1683: Cannot open /var/lib/alsa/asound.state for reading: File exists
Found hardware: "HDA-Intel" "Realtek ALC256" "HDA:10ec0256,1a582001,00100002 HDA:8086280b,80860101,00100000" "0x1a58" "0x2001"
Hardware is initialized using a generic method
Found hardware: "HDA-Intel" "Nvidia GPU 84 HDMI/DP" "HDA:10de0084,00000000,00100100" "0x0000" "0x0000"
Hardware is initialized using a generic method

In summary, headphones are not detected automatically. I can hear using headphones after selecting them inside pavucontrol, but even inside pavucontrol, headphones are shown as "Headphones (unplugged)".