I have run into that issue. Same vendor, model, color, speed, size, voltage, everything identical about the ram. Except for the serial numbers. They were 10 apart. Literally 1 was made 9 sticks after the first. And they would not work together. I've also had ram so far apart it was laffable work. 1.5v and 1.65v, 2 different vendors, sizes, even speeds and they worked perfectly at the lowest speed and 1.65v.
When it comes to ram from different packages there is only One guarantee. There is No guarantees. The ram either works, works after adjustments or doesn't work at all. That's it. Pot Luck. And you will not find out until you try. You could spend weeks in rma process, swapping sticks out a dozen times and still not get lucky, or get lucky the first time. Impossible to tell. It's why it's strongly advised not to mix ram, but to purchase what you want, when you want it, even if it means taking a loss on resale later.