I would suggest you do what I did but for i3. It looks like RebornOS also does an I3 version, I would download that install it in a VM download and run the Cura appimage and see if the open file dialog doesn't crash Cura. If Cura appears to run correctly get a list of all the explicitly installed packages using
pacman -Qe >reborn_installed_packages.txt
You will need to get that file off the VM and on to your computer, if you haven't set up virtual disks I would suggest email it to yourself from a web email.
Get a list of the explicitly installed apps from your Manjaro I3 system and then use diff to find out what packages are installed on reborn and not manjaro. It's probably worth stripping off the version numbers of the packages in a text editor using find and replace with a regular expression \s.* and replace with nothing.
diff reborn_installed_packages.txt manjaro_installed_packages.txt | grep '^<' | cut -c 3- > on_reborn_but_not_manjaro.txt
I've got to thank iAsk.Ai for the regular expression and the diff command syntax, I would have had to do it all maunually otherwise