Volume applet, Keyboard brightness, & Touchpad not working

Hello all,

I'm welcoming myself in this forum!
I've been using Mate for Ubuntu 64 bit for years now. Yesterday, I managed to install Ubuntu 20.04 MATE in my Lenovo Ideapad Slim 3 14IIL05 model. But I;m having some issues with hardware controls:

  1. Touchpad: Apparently, this is not working since there is no option for it in the settings (requires me to use a mouse):

  2. The volume control icon is permanently muted though the volume can be adjusted in the Sound Preferences.

  3. The brightness keyboard control are not working (F11 and F12), though it is adjustable in the Power Management -> Display

  4. The bottom panel remains empty while applications are currently running.

Regards