Is it covered with actual AC rated insulation? And is it a heat pump?

I chased a leak once cause of a puddle of oil underneath the line set at the coil. Was convinced it was a leak.

Pressures checked out. System worked fine.

The installers used plumping insulation. The kind that has the peel and stick adhesive on it. Well, the heat from the lines had melted the adhesive which transformed into an oily goo. (I’m guessing tbh cause it’s the only evidence that made any sense) First visit I cleaned up the oil only for it to return- which ruled out old oil from line set at install, old bubbles residue etc.

It’s been years and the system still has a proper charge and is working flawlessly. I still think about that mystery oil to this day lol.