I would use bleach and noting else, along with much brushing...you know, the elbow grease.

You remove the the fungus the old way...scrub it away..then use soap water and rinse and forget about the vinegar.

It's all about breaking through the fungus and it has little to do with a low pH.

then mix a bleach solution according to the directions on the bottle and spray it on. Scrubbing removes the surface stuff and the bleach kills any of the mycelium left behind.

Mixing bleach with anything but water or dish soap is a bad idea.

The OP can try the other stuff but if it doesn't work, scrubbing then bleach is the way to go.

Not mixing them together, but using one or the other cut with water and soap.

on a concrete picnic table and benches that gets green mold on the north side. It works well. No smell, lasts for a year, doesn't kill the grass. I use a garden sprayer. There is no scrubbing involved at all.

I use Wet & Forget shower/tub cleaner as well. Use it after a good cleaning and never scrub again. I haven't had to scrub the tub or shower surround for over 4 years. I make sure it's dry, spray it on, let it dry for a few hours and rinse it off. That's it.

I don't have experience with vinyl siding, but I'll be a lifetime user of Wet & Forget products.