No diverter is present there at all. There’s a bunch of things going on here that could be causing this problem and I think it would be best to address all of them at once:

• No diverter
• No drip edge present along gutter, and I’ve seen water drip from soffit vents
• Vinyl siding was installed over original wood composite. It’s questionable whether the step flashing is effective given the setup
• Gutter potentially too small - I have to clean it out like 6 times a year even with gutter guards over most of it