Trans-Neptunian Dwarf Planet near Heliopause Is there any reason to think a Trans-Neptunian dwarf planet, the size of Pluto, could not exist in a Keplerian orbit 120AU from the Sun?

If such an object existed, and came within 0.1AU of the heliopause, is there anything about the environment near the heliopause that would prevent a stable orbit.
Heliopause is believed to be at a distance of about 123 AU away from the Sun. Now, if you look at the list of farthest body in the solar system, you will see two bodies located approximately at that distance: 2018 VG18 and predicted FarFarOut (124.12 AU and ~140 AU from the sun as of June 2020 respectively). They are considered the farthest TNOs in the solar system.
For comparison, Voyager 1 and Voyager 2 are the two space probes which left the solar system is now 149.36 AU and 124 AU from the sun as of June 2020. Also you can see some of the near-parabolic comets originating from that distance.