I had SN/KMD swap that stayed on 'pending' for a few hours. It stayed as 'pending' after HyperDEX restart as well.
Not sure if it qualifies as a 'stuck' trade, since the trade never started. In any case, pending trades should probably after some time be automatically changed to 'cancelled' or whatever you decide the status for 'never started' swaps will be.
I had SN/KMD swap that stayed on 'pending' for a few hours. It stayed as 'pending' after HyperDEX restart as well. Not sure if it qualifies as a 'stuck' trade, since the trade never started. In any case, pending trades should probably after some time be automatically changed to 'cancelled' or whatever you decide the status for 'never started' swaps will be.