No one makes a cent by selling fake 7414.
No, but by selling parts that has been wrongly marked because or a mistake, yes.
They are already down to cent range even form TI, let along from many cheap but legit Chinese companies.
Btw, if I can send you a picture of the IC, with a badly printed TI logo, you'd know there is a broblem
Before questioning parts, first question your decoupling. If your naked eyes can see it blinks, it is definitely not "IC speed", therefore think more on external circuit.
I did, and when my circuit came down a 3.7V lithium battery, one 74hc14, one resistor, one LED, and one potentiometer, when my (admittedly cheap) multimeter showed 0V on AC voltage on the input, 1.9V DC voltage on input, and the led was randomly blinking, my conclusion is : this part HAS a problem. They were sold by 10 pieces and none of them have any hysteresis.