BODY:
When having emacs (version 27.0.50, but also works with 24 and presumably all other versions) auto start, either through the session saver, xfce Application Autostarter, or through standard methods such as .bash_login, emacs will fail to properly load in XFCE, as well as exhibit strange behavior.

CURRENT RESULTS OF TESTS:

# Session saving emacs:
When saving emacs through the automatic session saver in XFCE, then logging back in to load the session, emacs will launch in the proper virtual desktop and will act normally. A second instance of emacs (the "bad" one) will launch in the first desktop. When attempting to close the bad version of emacs, it relaunches. From my tests, bad emacs must be closed a total of 6 times for it to stop relaunching. The normal emacs session remains fine, and whether bad emacs exists or not, will close immediately without any more instances.

# Autolaunching emacs on login
When launching emacs through the XFCE Application Autostart, a bad emacs will be started. A normal emacs will not launch.

# Using .bash_login to autostart emacs on login
This is exactly similar to the previous experiment.

All of these issues persist whether the user has multiple desktops or one.

ISN'T THIS JUST EMACS?:
From my conclusions, no, it's not just emacs, and XFCE plays a roll. When testing emacs autostarting in different DEs (MATE has been tested so far), emacs does not exhibit this behavior. This seemingly has no link to how XFCE autostarts emacs (except in the first experiment case), as this issue persists even when started separately from XFCE's startup services. There must be some sort of issue with emacs and xfce starting at the same (technically near) the same time. I have submitted bug reports to the GNU Emacs bug reporting system in the case where XFCE isn't the full culprit here.

EXTENDED INFO:
Distrobution: Debian Testing, 4.14