Yeah, it's Florida....sourcing water its not an issue
The reason why I think the way I do is that I have an area of my pool where the pool wall and property line wall are about 3-4ft apart (it's probably 5 ft if measured accurately as that would be code). That area of the ground, in the winter, always looks sopping wet and never really dries out. It's also shaded quite a bit due to the low sun exposure. Because of this, you'd swear I have a leak there, but I don't. Then, when the summer comes and the sun is a bit higher, the surface dries out.
It's all just retained water and it shows up even here in the desert because of the heavy clay soil, some drip irrigation there and the low sun exposure in the winter. I dod a test dig and, sure enough, the soil is saturated down at least 18". I wouldn't do any drainage there simply because the clay will hold the water more tightly than a drain pipe could pull it away unless I dug out that entire area and replaced the clay with sandy soil, DG and crushed stone. Really not worth the effort at all.
So, in my opinion, that area is just building up water over time and staying wet because there's no where for the water to go. It's entirely possible that the sheer could have a tiny leak too, but I bet it's more just from rain exposure and wet kids and people jumping in and out of the pool there.