This argument that QM does not falsify relativity because QM deals with the quantum and Relativity deals with 4D spacetime, is like saying Relativity does not falsify Newtonian mechanics, because Newtonian Mechanics deals with 3D space and not 4D spacetime
Let's look at this argument a little more closely.
As you stated earlier, treating time as distinct from space still works pretty well most of the time (just as using classical mechanics to model macroscopic systems/phenomena is easier than using QM and pretty much gives the same answers). However, Einstein (and others), demonstrated first through theoretical and computational work and then empirical investigation that the "classical" view of time was inadequate and flawed, because it produced inaccuracies in models for things like celestial orbits, or measurements of the speed and motion of light. The framework of Newtonian mechanics predicts that, like everything else, the speed of light should be obey the additive property of velocity, and (as it has no mass) gravity shouldn't have any effect on it. However, neither is true. Special relativity took care of the first issue, and general the second.
Now, this in no way is meant to encapsulate the entirety of relativity or its importance physics, but rather to illustrate an issue with the idea that QM somehow "falsified" relativity. Relativity didn't just provide an accurate model for planetary orbits or show provide a framework for understanding Eddington's observations of the 1919 eclipse (the effect of the curvature of space on light and how this entails that light should be deflected by things like planets/moons). Like QM, it demonstrated fundamental problems with the classical framework and corrected them.
Yet you assert QM has falsified relativity, because according to your interpretation of various summaries or explanations of research you haven't read leads you to believe that the results of EPR, Bell, Aspect, and others demonstrate not just that there is some incompatibility between the two theories, but that one falsifies the other.
The issue, however, is that the various problems within the classical/Newtonian framework which were solved by relativity aren't a part of, nor can they be, QM. In other words, quantum theories consist of a framework of interpretation which varies quite a bit between physicists, a formal, mathematical abstraction which is much more consistent, and various methods of experimentation (also much more consistent between researchers). The mathematical models and the underlying theory have been enormously successful at predicting observations given some experimental method. But all of this, every bit of it, is true of relativity too.
There is one big difference though. Experiments in quantum mechanics consists of preparing some system and ending up with some results, and using the formalisms of QM both as a integral part of the experimental design, and even more so to represent what took place during the experiment and what the result was. What it doesn't involve is observing whatever it is that these mathematical abstractions are supposed to describe, or even if they are supposed to describe (rather than represent).
Imagine a giant coin machine. You can take all the coins you have, providing the are real coins, and poor them into this machine. You can't see what happens, but after a little while a certain number of dollar bills will come out. The amount which comes out is always equal to what you put in, but as there are different ways in which the same amount of money can be divided in bills (e.g., 5 $1 bills vs one $5), you can't know exactly
what bills you will end up with, just what the total value will be. Also, given your extraordinary forensic mind when it comes to mathematics, you have formulated a good predictive model based on previous observations (i.e., other times you poured coins in) and your knowledge of combinatorics, probability, etc., you also have a pretty good idea given
n number of
x coins (of any type, and any combination of these types and amounts), how the machine will end up breaking down the total value of the coins you put in and outputting particular numbers of particular bill amounts ($1, $5, $10, etc.). You don't know what's going on inside the machine, though, because you can't see it, and although there is a certain regularity (predictability) to the way your coins are translated into bills, you aren't sure exactly how your calculations describe what's going on in the machine nor how nor why (does the machine randomly and arbitrarily divide the total amount of value of the coins into bills? Does it have a more general, but still not determined system? Does it start to turn the coins into bills almost immediately, or does it wait until no more coins are added to start dividing the total value into bills?).
In many ways, this is analogous to quantum research. We have inputs and outputs and mathematical models and symbols which work pretty well in a sense (akin to the way you know certain things about what will happen if you put a certain number of coins into the coin machine). But as all we can do is describe the before and after, that's all we can know for sure about what the models (the math) does: describe the before and after.
However, even with these restrictions, we can still show that it appears (despite measurement problems) that measurements in one region of "space" are related instantaneously to those in another region of space. And certain interpretations of this phenomenon appear to violate certain interpretations of relativity. However, different interpretations of either or both do not. Meanwhile, QM cannot account for a number of other observations which relativity does.
So why is it that the observations/experiments which relativity explains, but QM doesn't, don't matter (and don't "falsify" QM), but certain interpretations of certain measurements of QM violate certain interpretations of relativity?