Unable to use imgmount with Indiana Jones Fate of Atlantis on my Steam Deck

[Gagert]

I have a setup for RetroArch with the dosbox-core libretro core for both my Windows 11 PC, my Android phone, my Android tablet and my Steam Deck. For each system, I have to change the paths under autoexec in the *.cfg file which I use to run Indiana Jones Fate of Atlantis, and other games in which the *.exe file is within the CD/image file itself.

The autoexec commands in the *.cfg file of this game is as follows:

mount C "/run/media/mmcblk0p1/Roms & ISO/DOS Spill/Indiana Jones Fate of Atlantis"
imgmount D "/run/media/mmcblk0p1/Roms & ISO/DOS Spill/Indiana Jones Fate of Atlantis\atlantis.cue"
D:
atlantis.exe

I have experimented with using this instead as the second line in the autoexec, as it is with my other devices (PC, phone and tablet):

imgmount D "/run/media/mmcblk0p1/Roms & ISO/DOS Spill/Indiana Jones Fate of Atlantis/atlantis.cue" -t iso

This works flawlessly on my Windows PC, phone and tablet, but somehow this does not work on my Steam Deck. It just straight up looks like the imgmount command is somehow broken by using the Flatpak release of RetroArch 1.19.0 on my Steam Deck with dosbox-core 27b6dbe, both while launching RetroArch via the desktop mode or launching RetroArch via the "non-Steam" section in the Steam Deck frontend itself.

I'm not missing the atlantis.cue and *.img file on my Steam Deck, but somehow dosbox-core can't find those files on my Steam Deck. As said I have the same exact files on all my devices, with the exception of me having to change the paths under autoexec in the *.cfg file on each device to match the device's file paths for the game locations.