Yeah, I just think the issue is adding 5 pounds each arm. What I'm gonna do next week is switch to seated BB overhead presses. That way I can add 5 pounds total across both arms and work my way up from there. It's not ideal for my imbalances but I want to progress to more weight so I gotta make adjustments.
Be careful with the bb cause you don't have as much freedom with arm position and may put you in a position that shoulder might not like. Start light and feel it out! As far as the imbalance goes you could use laterals to make sure you keep pushing the weaker side! Side laterals, rear laterals, front raises! If you can locate the exact head of the delt that need more work you can add another exercise for that particular head.