Multi-File Installation GUI Failure

I’ve recently distro-hoped from Mint (Cinnamon) to Debian (KDE-Plasma). I use downloaded installers from as my basis for games, and in Mint, if I tried to install a game from downloaded files and there were multiple files, I would get one entry per file that I could then point Lutris to, so it could install each sequentially, it worked great.

In the new set-up (Debian/KDE Plasma), I get a single line that tells me X files. I can point to a single file, but not to the rest of the files. Naturally, the installation process fails.

Here’s a screenshot of the GUI. I suppose I could just install it manually and point Lutris to the game, but it’s weird that this worked fine before and suddenly doesn’t work. Is there a way to fix it?