Making the jump from Rofco B40 to Mono Harmony - help!!

Ok so I've scaled up my business and have made the progression from the Rofco B40 to a Mono Harmony deck oven. 

I have kept my entire process bulk fermentation, shaping and proofing the same. The issue I am facing is that whilst the loaves are rising, the scoring lines re-seal and then burst out the side further on in the bake. My gut is telling me it's too hot and dry in there, however I use lots of steam and have experimented with temps from 280c right down to 210c. Pretty much same result! I'm also not getting the blistering that I've been used to in the Rofco. 

If I could have any advice from deck oven users I would be so grateful!!