I think it is green mold or fungus due to to much wet and dampness and lack of air flow. So then yes it is fungus.
Me thinks.

I tend to agree, but it hasnt been overly wet these days so not sure why I would have it... Also, its an open garden with good airflow and mid-70s temps.
I'll monitor it and see if it gets worse

Hit it with a 3% hydrogen peroxide spray. You can generally find it in bottles in the pharmacy section of a grocery store as a topical antiseptic, and Walmart typically carries it already in a handy dandy spray bottle.

It kills bacteria, fungi, and all sorts of other problems without hurting the plant. Even fresh seedlings can take up to around 10% H2O2 with no ill effects, and it can even help plants with root rot from overwatering recover (the peroxide breaks down into regular water and oxygen, helping to aerate the soil).

Only downside is that if you water heavily with peroxide, you will sterilize the soil, which is bad if you're trying to promote a healthy biome.

But yeah, I've used peroxide spray on my indoor sprouts for years as a way to avoid damping off.

If it is on the woody part, and the plant looks healthy I would just keep an eye on it. It can be like the stuff that grows on tree bark in slightly shaded areas.

Although a bit of the peroxide would not hurt if not overused.