Alright, went out and cleaned it up. Took off that clamp, it was literally clamping nothing. If I had to guess they probably had it around the seal at one time.
Cleaned up there appears to be some sort of caulking material that was put on around where the valve connects to the tank and that looks like where it leaked out from. Must be a slow leak, but a leak nonetheless.
Is there some sort of special caulk they use, or should I just try the flex tape? Flex tape seems like the easiest solution but not sure how well it will seal since there is caulk all around that seam.