This P-Trap was leaking. Disassembled, looked like it had been hacked together, including the sink drain along with the plunger which did not work correctly.
Removed all old parts, replaced with new. No leaks, and the plunger worked great.
First image here is the job completed, working great.
The problem was water under the sink, on the bottom of the shelf. (Ooops, my picture was slightly out of focus).
The drain was disassembled and evaluated. The problem was found, but also the hacked previous install. And as the drain control didn’t work either, it was decided to repair all.
First order was to get the parts:
Begin reassembly process:
Completed.
No leaks, and the drain is easy to lift and set back down with the plunger.