I just answered this elsewhere, but it makes sense to drop it here, too. The tl;dr answer... YES, the cable matters A LOT.
I just rode a long support train with Sweetwater and PreSonus on this, and I'm going to give it you in a nutshell. I have had a Quantum 2626 for a couple of months now. Not only would it sporadically not show up in Universal Control, but at least once a day, it would randomly fall into fault mode and freeze up (froze up my iMac on several occasions, too). All the front panel input LEDs would suddenly glow solid red for 5 seconds, and then the unit would be effectively dead. Only a restart would bring it back. Ultimately, the problem was determined to be the cable. I was using the StarTech 2-meter passive 20 Gbit/sec cable that Sweetwater bundled with the Quantum. On the direction of PreSonus, I swapped that cable out for an Apple 0.8-meter active 40 Gbit/sec Thunderbolt 3 cable, and all my issues vanished. The cable, as it turns out, is an extremely critical component in the use of an interface like the Quantum 2626. So spend the 40 bucks, and get that cable.
It's not the cable you want, it's the cable you need.