Portable Planter (Digger Biomechanical) Keeps Disappearing

I selected Digger Biomechanical as the internal corp for my Portable Planter (the default one you get at the beginning). I built it at my base, and it started gathering ore normally.

However, after a few hours—when I return to my base after exploration or log back into the game—the planter has completely vanished. There’s no destroyed remains, no item in storage, nothing.

This keeps happening every time.

Is this a bug, or am I missing some mechanic or requirement?

Any help or clarification would be appreciated.

Thanks in advance!