KDE Dolphin error "Argument list too long" when trying to open anything

[split notch]

I'm using Dolphin as my file manager under Hyprland, and sometimes it stops opening files, always showing the "Argument list too long" error on the top banner when I try to double click anything (e.g. text file, photo, etc...). Sometimes a reboot / Hyprland relaunch fixes it for a while, but I eventually the issue always returns. I don't even know where to begin looking for the root cause, so I'm hoping that someone can help.

[weak lark]

next time it happens, try running
xdg-open <path to that file> (remove the <>) and tell me what you find

if the error reproduces, show the full output

if it doesnt, try running dolphin from commandline and then opening the file

[split notch]

Well xdg-open just works with no issues, dolphin command line shows the following errpr:

kf.kio.gui: Failed to launch process as service: "[e-mail]" "System.Error.E2BIG" "Argument list too long"