Plumbing Stacks Causing Ice Dams

Hi all. Hoping for help with a problem I first noticed two years ago. We have never had a home with a metal roof. We took possession in the winter and immediately noticed a large ice dam on the upper roof. I asked the builder about it and at the time he thought it had to do with the bathroom vent in the soffit. In the spring, we were often startled by the sound of the ice slamming down onto the lower roof. I also noticed damage to the gutters, bends and generally pulling away from the fascia. In spots, the water passes behind the gutter. I decided to replace an 86 foot run of gutter to alleviate that issue and discussed with the builder who insisted the damage was due to the lack of snow stoppers for the first winter. This winter I started looking closely at the melting from the plumbing stacks on both the upper and lower roof and they directly line up with the ice. I have sent the builder photos and he agreed it was the stacks but discussed it with the roofer and the plumber and both were perplexed. Solutions varied from a new boot, to extending the the stack. They visited and opened the attic hatch but didn't go in, not wanted to disturb the insulation. They pronounced again that it was the vents in the soffits and offered no solutions. Here we go again, another winter and again there is large ice accumulation below both the upper and lower stacks. I'm at a total loss as to what to do. I have reached out to the local metal roofing contractor and received no reply. I am new to this area and getting help is difficult. I have put off the gutter replacement to the spring, hoping I can get this figured out and repaired once and for all. I have the approved drawings, which specified an asphalt roof. From the builder - "The upper roof is a "hot roof" with Min R-31 insulation right to the sheathing with the pipe going straight through. The lower roof is is R-60 insulation vented roof."

Any help is beyond appreciated. Thank you.

A zoomed in view of the boot.

I am hoping to find that out when the builder comes to take a look. The problem with the upper roof is there is no hatch. The builder wrote it was sprayed with closed cell spray foam to the underside of the roof sheathing.

Thank you Todd. That sounds like a manageable problem.