Typewriter Ribbon Advance Issue?

I have a Royal TQ 740 electronic typewriter in good physical condition, with unknown history. Everything on the machine works exactly as expected, except for one problem: when the machine executes a carriage return, the ribbon cartridge's takeup reel is rotated the wrong direction and the ribbon bunches up inside the cartridge and fails to feed again until the slack is manually removed.

I see how the ribbon feed mechanism is driven when the carriage moves left to right as in normal typing, but I don't see any obvious mechanism to stop it rotating backwards on a carriage return -- except that it has a sort of friction clutch, so my hypothesis is that this may be gummed up. However, it may just be there to avoid stripping gears if the ribbon gets stuck or reaches its end.

The machine does have a mechanism to lift the cartridge completely off the spool drive pin, which it does for repeated spaces (to avoid wasting ribbon) so perhaps it should be doing that during a carriage return. However, because that function works during spaces, we know that the electromechanical mechanism to drive that does work, so there's no obvious reason why it wouldn't be initiated on a <CR>.

I do have a background in electronics engineering, so I'm comfortable digging into the machine; I just don't have experience with these particular machines.

If you happen to know the fix for this, I'd appreciate your input.