I know this topic comes up occassionally and wanted to share my own recent experience.
For those of us that connect our Stage Traxx iPad/iPhone directly to the USB input on a mixer, one of the challenges we hit is the length of the USB cable (i.e. how far away your mixer can be from your iOS device).
Most mixers use a USB 2.0 input (in fact, I'm yet to see a mixer with USB 3.0).
The maximum length a USB 2.0 cable can be is 5m / 16.5 feet - go longer and you start to risk performance degradation.
The solution is what they often refer to as "buffered" or "active" or "repeater" USB cables.
These cables usually have some extra electronics in the cable (often at the mid-point) that 'boosts' the signal allowing for longer cables.
Some require an external power source (a bit of a pain) but most can draw power from the source device via USB.
The next challenge we face is that these cables are mostly designed for printers, and not audio. Printers are way more forgiving of delays/slow speed of transfer compared to audio. So, not all buffered/active/repeater cables are equal, and will work reliably with audio.
When I first hit the USB cable length problem, I went searching for any post (here and elsewhere), or reviews on Amazon/eBay, from people confirming that a certain cable worked with audio devices reliably. That was no easy task. The one recommendation I recall from these forums was for a Lindy brand cable that wasn't available in my country, and shipping fees were going to be unreasonable.
So I took the plunge on a cable from Amazon that, on paper, seemed to tick all boxes. Being from Amazon, I knew that if it didn't work, I could easily return it!
The cable I purchased, that I can now confirm is working for connecting my iPad to my Behringer X32 mixer is this one:
PremiumCord Active USB Connection Cable with Repeater 10 m USB A Male to B Male USB 2.0 High Speed Cable 2X Shielded AWG20/28 Black Length 10 m
https://www.amazon.com.au/dp/B07HX4DJ79
Maybe others can add links to the cables they have had success with (failures are also good to know so others can avoid) to this thread as a searchable reference here.