CSS error in Chromium based browsers

VitalPBX 4 admin page has a bottom bar with action buttons like Save, update, etc. It is stacked at the bottom of the page in the editing area.
If “Multitab” setting for the user account is turned off, then in Chromium based browsers it is covering the bottom part of the editing area. The only solution to see the covered area is to zoom out the whole page or turn on Multitab setting in user profile.

Tested in the following browsers:

  • Google Chrome (Linux and Windows)
  • Microsoft Edge (Windows)
  • Chromium (Linux and Edge)
  • Brave (Linux and Windows)

This problem doesn’t exist in Mozilla Firefox on Linux and Windows.

I’m a new user and I allowed to upload only one image so I tried to merge the screenshoots into one image.

  1. picture: Display bug in Chromium based browser fully scrolled down and Multitab setting is OFF.

  2. picture: Working well in in Chromium based browser fully scrolled down and Multitab setting is ON.
    Note that the TABs are stacked at the bottom.

  3. picture: Same page in Mozilla Firefox with Multitab setting is OFF:

  4. picture: Same page in Mozilla Firefox with Multitab setting is ON:
    Please note that the TABs are not fixed but scrolling out. The TABs are stacked in Chromium based browsers.