Application not filling desktop & Brighness Control Light not working

Hi, I have installed UB 20.04 now and absolutely love it. The UB team did - and does - a magnificent job on the distro and I am sticking with it for almost 3 years now, without even looking at any other Linux distribution.
The new App-Menu is absolutely cool.

Now, after installing UB 20.04 I came across two small glitches. (For the sake of saving time, I put them both into the same question. I hope this is okay. )

One glitch is that a few applications don’t completely fill the available space on the desktop. I have an open space below the applications that is about 5 mm high. I can see the background of the desktop image through it. This affects apps like Nemo, Firefox, Eclipse and LIbreOffice, but not others like Nautilus or Chrome.

Screenshot from 2020-05-11 11-25-57

The second glitch is with the Brightness Controller Applet: the “Dim” sliders do both work, but the “Light” one does not. I have to open the Power Settings to adjust the screen clarity.

Are there any adjustments I could make?

Re brightness controller. Can confirm this. GNOME 3.36 broke the applet - unfortunately no one picked up on this before the release. This needs a fix - this is the bug report to track

I can’t reproduce the nemo, libreoffice issue when maximising. I’m using Pocillo theme - also tested Pocillo-dark-slim. What theme are you using?

I am using Ultimate Delta Blue theme from here. Using a different theme actually fixed the issue. Interesting, though, that this is the impact of a theme. I’m going to go through the css (the Agatha Christie thing) to figure where the problem is originated.

Thanks for pointing to the issue with the Brightness Controller … should I do something … like filing a #MeToo?

Lol. No need for a me too. Offers to resolve will make things appear faster…