I have the Megaton Smoking Rocketeer class mod and points in the skills trees that means I can keep Iron Bear up and in automatic mode constantly. This works fine no matter where in the game I am.
In co-op though, this does not happen. Iron Bear cuts out after a short time just as if I have another COM equipped. I noticed this at the Slaughterstar 3000 and on Nekrotefeyo - I don’t often play co-op. I’ve tried switching class mods and then back again to the preferred one - no change.