Which particular app?
Being Chromium based, Vivaldi might be a valid workaround.
sudo pacman -S vivaldi
Brave is available from the official Manjaro repositories, and yet you have opted not to use it. Try uninstalling your current instance and installing the recommended version:
sudo pacman -Rns brave-bin
sudo pacman -S brave-browser
I note that both brave-bin and google-chrome (and all other software sourced from the AUR) need to be fully rebuilt after each and every Manjaro update. If you have not done this, it’s possible that problems can accumulate over time.
Related: Best practice method for updating your system
Help us diagnose the problem:
Please create a new User account (for testing purposes). Reboot, and login to that account and verify whether or not you experience the same issue.
If the issue is no longer apparent, then this will indicate that the cause is limited to your main User profile, and this information will be invaluable for those who might wish to help; giving some direction; a place to start.
In the meantime, please provide system information as described (below). With those details given, I’m sure someone will be able to help further when they are able.
Regards.
Welcome to the Manjaro community
As a new or infrequent forum user, please take some time to familiarise yourself with Forum requirements, and the many ways to use the forum to your benefit.
To that end, links are provided (below) - Please use them.
Be prepared to provide outputs from various commands when asked. It’s equally important to provide as much actionable information as possible in your first post, rather than simply indicating there is a problem.
Waiting for someone to blindly ask questions is also counter-productive – typically, nobody has a 
at their disposal – Instead, please help others to make informed suggestions, based on information you provide.
Update Announcements
The Update Announcements contain important information and a Known Issues and Solutions section that should generally be checked before posting a request for support.
System Information
While information from *-fetch type apps might be fine for someone wishing to buy your computer, for Support purposes it’s better to ask your system directly; 
Output of the inxi command (with appropriate parameters, and formatted according to forum guidelines) will generate information useful for those wishing to help:
inxi --filter --verbosity=8
or the short form (preferred):
inxi -zv8
- inxi man pages (Arch Manual)