tl;dr crank-no-start issue if extra transponder key in pocket. Computer antitheft behaviour, or dying fuel pump coincidence?

Had an interesting experience a few weeks back. Was traveling and brought a spare key with me just in case. 2016 T4R TEP, not keyless start.

Was carrying around both keys in my pockets and all day no issues, everything is normal. (I've previously done this many times, every time I travel from home.)

Next morning, extra key still in my pocket, truck cranks and cranks but not firing. Repeat this a few times no luck.

It dawns on me the computer might be "confused" by two transponder keys and not activating something something? One of the keys is 3rd party cut and programmed but has always worked fine (other is OEM original.)

Put the 2nd key about 15' away, and then try again, after a few long cranks, a few sputters, and then a final attempt is normal.

Happened again 2 more times that trip. Both times recovered by moving the 2nd key away.

No problems in 3 weeks since (only ever having one key on person.) No codes ever thrown.

So... weird transponder chip key computer issue? Or dying fuel pump acting up for a few days and not since then?