SUMMARY

When I close the laptop lid and then reopen it, the Wi-Fi gets disabled automatically, so I have to re-enable it to make it work. The same happens with the Touchpad — it stops working and I cannot move the cursor. When I navigate to the Touchpad settings, it is automatically set to “disabled", If I turn it on from there, it starts working again.
For your information, I have already selected “Do nothing” in the Power Management settings for when the laptop lid is closed.
BTW I found the fix which is mentioned in the Additional information section.

STEPS TO REPRODUCE
1. Close the laptop lid.
2. Reopen the laptop lid.
3. Observe that Wi-Fi and Touchpad are disabled.

OBSERVED RESULT
After reopening the laptop lid, both Wi-Fi and the Touchpad get disabled.

EXPECTED RESULT
Wi-Fi and Touchpad should remain functional after closing and reopening the lid.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: EndeavourOS (This also happens on other KDE-based distros)
KDE Plasma Version:  6.4.5
KDE Frameworks Version: 6.19.0
Qt Version:  6.10.0

ADDITIONAL INFORMATION
I found a workaround that fixes the issue:

FOR Wi-Fi:

Edit the file /etc/systemd/logind.conf using sudo nano /etc/systemd/logind.conf.

Replace the following lines:
#HandleLidSwitch=suspend
#HandleLidSwitchExternalPower=suspend
#HandleLidSwitchDocked=ignore
with:
HandleLidSwitch=ignore
HandleLidSwitchExternalPower=ignore
HandleLidSwitchDocked=ignore

Restart. This prevents Wi-Fi from being disabled when the lid is closed.

FOR Touchpad:

Open Keyboard Shortcuts and search for “Touchpad”.

Disable the option “Touchpad Disable”.

This prevents the Touchpad from being automatically disabled when the lid is closed.