2018 Lincoln Cent Planchet Flaw

First of all thank you for the last several replies since I last responded. I did soak it in acetone for a little while until I felt comfortable removing it. Aside from the obvious zinc rot, which is more than obvious due to the upper ring being a groove and incuse therefore exposing the core, the acetone did take away quite a bit of yuck stuff in the groove which showed more detail. The displaced metal around the upper ring is easier to see now. The displaced material around the ring leading up to and away from the devices had no effect on the devices at all. If this was something that occurred post-strike I believe I would see damage to the legs, serifs, shield, scroll, etc... but they are all undamaged and intact. The bottom raised ring is also interesting in that it stops and continues at the bottom tip on both sides of the shield and enters and exits the left side of the scroll with no damage to that area as well. In addition, where the grooved ring begins above UNITED, the rim is completely intact which should have been flattened had this been PMD, IMHO... So...... last night while searching another bank roll, I found yet another 2018 Philly Shield with the identically positioned discolored ring on the reverse as on the original Cent in this post, very odd for sure! That coin was only discolored and the surface and fields do not display any noticeable ridges or grooves as does the original coin in this post. I took several better pics of the "dipped" coin but I'm not going to post them unless someone requests because I don't like "beating a dead horse" as I previously said a few days ago...lol. I will post the additional cent I found last night for comparison. And John1, thanks for the suggestion to maybe submit the coin. I'd think ANACS would be my best bet for something like this? Do you or anyone else agree? I've always just been a collector for fun and never pursued submissions but this one is killing my curiosity. I know it's not a game changing coin but I'd like some closure without throwing out too much $$. Thank you for all the discussion and insightful answers and suggestions.

I believe these are PMD as well, although I'm not seeing the zinc rot others are calling this. This is all residue and staining from another liquid-soaked cent laying on top of it (IMO). You usually see this from coins left in cup holders as coffee and other acidic drinks drip onto the coins, as pointed out before. It's not what most people think of PMD as (scratches, dents, parking lot coins, etc.) but it's damage in the sense that the coin is discolored and likely has some minor corrosion underneath.

If you're dead set on sending it to a TPG, ANACS would be the way to go. They're cheaper and better at labelling minor or obscure errors and varieties. However I am very confident you won't get the result you would like and I don't want you to "throw out" any money, so I wouldn't advise it.