First, before even reading the article, it's worth noting that among the many ways that I'm a relativist is that I'm a "perspectivalist." I don't actually like that term, because it suggests that I'm necessarily talking about the perspectives of persons when that's only a subset of it. I think that things are relative to "points of reference" (human perspectives, in particular places at particular times, being one set of points of reference) . . . although I don't like that term, either, because for one I don't want to suggest realism about points, and also people think of "frame of reference" in the physics sense, which is a more limited idea than my view. I haven't thought of/don't know a better term to use for it yet, though, so I use "perspectivalism."
At any rate, on to the article:
So first, this is partially because I don't know enough about how it is achieved, perhaps, but I've always been skeptical of the notion that we conduct experiments where we know with any degree of certainty that we're looking at a single photon, electron, etc. at a time. For one, obviously we can't check such things with our unaided senses. We have to rely on what machines are telling us is the case, and they can only tell us what we've constructed them to tell us, in whatever manner we've devised for them to indirectly tell us something.
The problem is both a control issue--how do we really know that we're only releasing a single photon, electron, etc.? And a knowledge issue--how do we know for sure that (a) we do finally have a correct model of subatomic structure (it turned out to be the case not too long ago that we didn't have the correct model), and (b) we do have a complete model, so that we know with any certainty that there aren't other things going on--other sorts of phenomena that we're simply not aware of yet?
Aside from that, what this experiment is actually doing is taking a pair of supposedly entangled photons (I say supposedly because I'm not sure how we're observationally confirming that that's what we have) and splitting them so that Bob observes m re his photon, x, and Alice observes n re her photon, y. Theory has it that x and y should have a specific relationship, and m and n are not consistent with the relationship x and y are supposed to have.
So the first obvious question is this: if we're observing x and y to have a different relationship than they're supposed to have (and this is supposing that we're observing both x and y, which from my scan of the experiment (the actual paper is here, by the way:
https://arxiv.org/pdf/1902.05080v1.pdf), on the one side we're actually observing the classic "interference pattern," we're not really observing the properties of a single photon), then the theoretical notion that x and y would be incompatible with respect to m and n is simply wrong, and insisting that it's correct is an example of theory worship.
The bottom line is that Bob and Alice are observing two different things in response to two different things (we're talking about two different photons). The supposed problem arises because of what theory proposes about what they should be observing about their two different things. Curiously, we interpret this as the theory being correct rather than noting that theory doesn't gel with what we actually observe, thus we are going to need to revise our theory at some point.