Where did you order those from? That box is suspicious...

Can you weigh one? The fake cells tend to be much lighter in my experience.

Edit: Actually, my genuine cells have the exact same label. Check to see if they weigh 46-47g.

Yes, 46-47g..

DAMNNN!! Same result.. but I think I may have found the cause…
I thought it was the battery weight..the unit would “brown out” and reboot..but I observed the fc lights still on. Thinking it was a lot of amp draw..
Then I remembered flying it on a 550mh 1s.. did full throttle “punch outs” (as pathetic as they were).. it didn’t “brown out”.. I was seriously gonna try another FC..
As I tested.. I would get 1/2 throttle, and it died, I held the quad (to keep it from lifting off).. same result. So it’s NOT the weight!
Plugged in a 1s lipo.. held, full throttle no issues..
It’s gotta be the wires / battery connections…
The voltage on the 18650 was still at 4.09.. so it has power..
I LOVE TROUBLESHOOTING!!!
No, seriously I do!
“Your only as strong as ur weakest link..”

It may be exactly what V-22 was suggesting earlier on in the thread: "using the 18650 cell holder is a major bottleneck in performance".

Try direct soldering wires to a Lion cell to see if the performance improves.

.. did some more digging.. and I believe you are correct. When I read the suggestion about the “18650 holder” being the issue .. I was thinking of weight NOT the battery connections.. the negative has a wound spring with what appears to be good contact.. but the positive is a cone/point… and this maybe the issue..
I may have read / seen something about this somewhere .. the solution was to use springs on BOTH ends of the holder.. and I will get rid of the wound springs and go to a “flat” type with more contact surface..
But gonna direct solder first.. to confirm..

Yeah, the wound spring terminals are a no go. Even Dave_C's original NLR build tutorial has a special mention on what cell holder type to use, and that the ones with the spring terminals won't work: https://www.thingiverse.com/thing:4769576

Direct soldering is definitely the way to go though!

Yup… SOLVED.. the battery connections were the weak point .. didn’t even wait to solder.. stripped the ends, taped.. flew no issues..
Even the 18750s I got from before were fine..
 Now, to shave down the prop guards.. see how much weight I can get off them or 3d print some..
 Then, add a gps module.. just because..

I have tested the 18650 holders Dave_C suggested (the Aliexpress version), and they are alright for 30A.
Not as good as soldering, but I find it to be an acceptable tradeoff for the convenience of switching batteries.
https://intofpv.com/t-18650-battery-holder-review

im probably going to solder.. as these are going to be plug in and go for the students. they will also be easier to charge (USB 1s lipo) as long as it is set to 4.2v. i would rather chance having it plugged in wrong rather than a kid installing the battery incorrect. Basically a "round" 1s cell. This rig will be for the kids that can handle the tiny hawks and want to "progress"... it will handle the outside a little better and give a longer flight time... until they need to print another frame....
Ill tell you, this is a great little QUIET rig....to bad the motors on the tinyhawks dont give up as fast as the FCs... I think Ive got a real good solution to the weak points of those little quads... got the FC, and frame.. just trying to get the camera/ mount finalized. School starts back.. ill send one, see how it holds up...