The fact that the bubbles worsten with the lights out backs up the theory that it is being caused by an algae film.
I've had lavishly planted freshwater tanks for several years. We're always pleased when those bubbles appear. It means that the plants are growing vigorously.
In order to produce this bubbling effect in freshwater tanks, there are a few important details. One is enough nutrients for excellent growth. The other is that there is enough carbon dioxide present in the water to fuel the plants. I think these two details could be manipulated in the marine tank to REDUCE this effect.
In order to make enough CO2 available to the plants in freshwater aquariums, we have to add CO2 and minimize water flow. So, I'd suggest increasing the water flow at the surface to blow off the excess CO2. More water flow in the tank will also help blow off the bubbles. A bio-wheel could be helpful in oxygenating the water. So would an effective skimmer and/or airstone in the refugium.
How is the macro doing in the refugium? Can you take a photo so that we can see how much macro you have? You need lots, especially since you likely have excess nutrients in the water. I've seen pretty pictures with just a few stalks of macro. To be effective, the fuge should be like a jungle. It's not supposed to be pretty! What kind of light have you got running over the 'fuge?
I would guess that instead of your PH being high, your PH is low. What are your water params? I expect that your phosphates and or nitrates are running high. Even if they are not, the algae can use the nitrates and phosphats as fast as they are being released. But, knowing the values will be helpful for us to make suggestions.