This does seem to be a template issue, specifically the CLEAN 6.1 Hero - Banner - Module. If you are comfortable working with templates, I would attempt a test of changing the Background Size of the banner image from Cover to Contain. -see Structure and customize template layouts - Knowledge Base
I would also recommend reaching out to the designers of this template for the advice! As HelpfulHero describes themselves, they provide Fanatical HubSpot Support: > "Yep, that's what's included when you go with the CLEAN Theme. I've got your back every step of the way."