On Steam Deck Mod Manager is not detecting Dredge.exe

[httpLovecraft]

I have installed the appimage file on Steam Deck and selected the install location as prompted (/home/deck/.steam/steam/steamapps/common/DREDGE). This allows me to browse/install mods from the Mods tab, but when I click the 'Play' button I get this pop-up error:
Dredge Mod Manager
Failed to start DREDGE.exe. Is the game directory correct?

If I go to the Settings tab, my DREDGE install location is shown (as above). If I click 'Open DREDGE folder', I receive this error:
Dredge Mod Manager
Couldn't open directory Launcher "xdg-open" "/home/deck/.steam/steam/steamapps/common/DREDGE" failed with ExitStatus(unix_wait_status(1024)).

Not sure why the mod manager cannot detect the exe now, as it did validate the directory for long enough to browse/install mods. Help!

[httpLovecraft]

Tried reinstalling as well as the same steps to reproduce as above but installing to the SD card instead of the deck drive, same issue.