After testing your rootfs more thoroughly, I noticed that neither firefox nor chromium can access the internet. Chromium gives the error "err_internet_disconnected".

However, pacman and others can access the internet.

Is it possible that chromium/firefox rely e.g on networkmanager/connman do detect the availability of internet?

P.S.: I'm using the rootfs from a sdcard and already noticed that some problems that I encountered are related to that. However, I guess that I solved most of them by remounting the sdcard using "mount -o remount,suid,exec,dev .... " before calling DeskChroot.