Hi, I'm a kinda new guy here (I posted a question in 2023). I love Zorin and have used it on and off. I now have it installed for good, I hope. I also love Brave and have used it for years in both Windows and Linux. I never had any problems with Brave in previous versions of Zorin, so I loved it when I found it installed by default in 17.3. However, it doesn't work at all. I customized it to my liking, and everything seemed OK. However, after I closed it for the day, it would not open anymore. I uninstalled and reinstalled. Same problem. Zorin 17.3, strangely, also felt very sluggish at times in my modern and powerful desktop, something that's perhaps geared to the Brave problem. This seems to be a bug because there are other users with the same problem. I hope the programmers solve it, because that's the only browser I like. Sorry for the rant.
I think the Zorin Group needs to switch to Vivaldi. Just my opinion.
There seems to be a spike in issues with browsers recently... but it's very strange because some people claim it's only with Chromium-based browsers, while others claim it's the opposite 
Is that your case as well? Maybe using another Chromium-based browser to contrast this, like Vivaldi, and then compare it to using Firefox.
Does Your System runs in Wayland or Xorg. Could could switch between both and compare if it is better.
You wrote that You have used Brave in the Past. Did You installed the .deb Version or the flatpak Version?
Do You have Hardware Acceleration in Brave active? How are Resolution and Refresh Rate set up? Is Fractional Scaling active? What Power Profile in the System Settings is active? What are Your Hardware Specs?
Thanks for the questions, but I don't even know how to check most of them. Performance power setting. I previously installed Brave flatpak. Xorg maybe?, I don't think I'm running in Wayland. No idea how to switch between them. Don't remember about hardware acceleration. I'm on 200% because of a 4K monitor, which looks just about right. Asus ROG Stryx X670E-F Gaming, Ryzen 7 9700X, FeForce RTX 4060 Ti EVO OC, G.Skill Flare F5-6000 32GB.
Update on my browser adventures. Installed Vivaldi thanks to Omnimaxus' suggestion. Great but almost overwhelming for me with the many choices. Worked with it for a while including mail, closed it for the day. Next day: Vivaldi doesn't open either! Notification: "Vivaldi is running in the background"
You can try the .deb version (=Zorin package) of Brave. The Zorin packages are better integrated into the system and cause fewer problems. If you install via the Gnome Software Manager (blue shopping bag on the taskbar), first search for the desired program and then you can choose between different package formats. Use the one from Zorin (and when you have problems with a program neither Flatpak nor snap).
However, uninstall Brave first before reinstalling it.
You can switch to Xorg by logging out and then clicking on your user when logging in. A cogwheel will then appear on the screen, which you can click on and then select Xorg. This setting is then saved until you change it again. By default it is set to Wayland.
To turn off hardware acceleration in Brave browser:
Open Brave browser on your computer.
Click the menu button and select Settings.
Switch to the System tab on the left side.
Find the Use hardware acceleration when available option.
Toggle the corresponding button.
Click the Relaunch button to restart the browser.
Fractional scaling you can disable in settings>display>fractional scaling (last point there).
If you can cope with vertical tabs, then I recommend zen browser (App Image), which is a fork of Firefox. I am looking forward to a fresh browser due out next year, ladybird.
That's probably it. Fractional scaling is one common source of display issues like the ones you're describing. Try disabling for a bit as a test, and see if that makes any difference.
To switch from Wayland to X11/Xorg:
Go to the Login Screen (not the Lock Screen). Simply reboot for that. On the Login Screen click on Your Profile so taht the Password Field appears. It has to be appeared. When it is appeared, You should see a Gear Icon at the bottom right Corner. Click on it and choose the Option ''Zorin Desktop on Xorg'' and then log in.
Then I would suggest to install the .deb Version. Because You have Zorin 17.3 it should come preinstalled. But when you don't have it anymore installed, You can install it with the Terminal Command sudo apt install brave-browser
It is in the Brave Settings under System:
Fractional Scaling, You find in the Display Settings:
