The match unit will function regardless or not if the jones plug has the end-game match set to on or off - it doesn't only control the end-game match (if enabled), it also controls "random" or some alternating features of games, where the thing in question changes every time a certain time a point value is scored. Even if a game didn't have these features (seems most do), I bet the match unit would still spin anyways for simplicity. Sometimes the bell itself is on the match unit, but I think that's mostly with Gottliebs.
I tried looking on a similar-era game's schematic (Seven Up, as this one is actually online) and failed to identify what could cause this besides the usual. A stuck playfield switch is really the only thing that would cause this but I am surprised that it would if the game was inactive.
If you start a game does a score reel and chime stick immediately as well? Perhaps you have an incorrectly gapped switch on the 100 or 10 point relay, whichever advances the match unit (it varies), this would NOT affect the chime and reel. The way the match unit works, is every time one certain point value is scored (10, 100, etc., also applies for multiples, 50/500 points would advance the match unit 5 times), it advances. There is not much else that triggers the match unit and of course the match unit does not shift or be reset between games.
I am guessing there is a misadjusted contact on whichever point relay carries the match unit on that specific game. Unfortunately I don't know if it's the 10 point relay or the 100 point relay in this case, I would think 10 point relay but the schematic made me think it might be the 100 point relay, this would also avoid "synchronized" matching so it must be that one (100).