I’ll try to investigate the cause of this bug, thanks for pointing it out! Do you remember exactly what icons you were selecting when the Dps wasn’t stacking?
unfortunately I don't remember. The best I can do without going back in is that if I had multiple types of DPC upgrades and upgraded one, it somerimes wouldn't change the damage until I bought more upgrades from a different item.
I have the bug too, it's manifested in different ways?
First it worked like this: when I equipped one ally and then another, it would completely ignore the second's DPS and just keep the first's. If I then unequipped the first ally, the DPS would drop to zero. https://www.youtube.com/watch?v=pueTHb7dQQo
And now it works like this: when I equipped one ally and then another, the second's DPS would overwrite the first's. If I then unequipped the second ally, the first's DPS would come back. https://www.youtube.com/watch?v=WpSK8_5IQc0
I'm not 100% sure what I did that made it switch, it's possible it was buying/equipping the next item but I didn't do before/after tests.