Anti-theft light blinking?

I recently bought the truck listed above, it only came with one key and fob. Purchased 2x fobs and blank keys on Amazon.

Issue started today; the original key wouldn't work. Flashing anti-theft light.

Did the open door, insert/remove key x2, open door x2, insert/remove key x1, open door x2, insert key, close door, turn to on then off, remove key. It worked 2x today.
Got the keys cut, programmed the fobs.
Went home and tried to program keys but the original didn't work again and couldn't get it to work.
Tried the open/close door, didn't work.
Tried the 30+ minute relearn on new keys, didn't work.
Tried disconnecting the battery, no help.