If you look at my screenshot below, this is a system monitor I use on my Mac. I had a similar system monitor when I was using Fedora Gnome before switching to EOS. Is there anything that is similar to this for easy monitoring of my EOS system?
What desktop or window manager are you using. Having this information would be helpful, because not all programs are made with all desktops and window managers in mind. You mentioned you were using Gnome before. Are you still using Gnome? If so have you checked the gnome extensions website for something similar https://extensions.gnome.org/?
For something similar it would as mentioned depend on your DE as as to what would be best. I would recommend looking up the package and seeing what optional dependencies are needed to make it work as expected. If it still has issues I’d report it upstream.