My USB skips up and down with the steering wheel buttons as well as displaying the song playing and source in the DIC. It also does this when I'm playing music from my CarPlay AI box.

 

Yep, use the left steering wheel levers to advance to another song (upper) or repeat (lower.) Use the right levers to increase volume (upper) or decrease (lower.)

Added some songs to a flush Flash Drive and it wasn't connecting. Before I was able to load on a new larger flush Flash Drive I tried for the 1st time Apply CarPlay. Forgot I had some songs in Apple. It worked the same as RKCRLR stated.

Downloaded same songs from my PC, all >1500, to a larger flush Flash Drive and all worked fine.

 

Not sure what yr you have, but there is an issue with the Playlists in the ‘24 when they developed the new MMI interface. They used the '\' instead of '/' to parse the directory information. Supposedly it’s going to be corrected in the next release of the MMI.

I used Apple iTunes to rip CDs, then transfer the files to a USB, which works perfectly in my Jeeps and Ram, and previously C7, but not in my ‘24 C8. The artists and albums work fine, but the songs play out of order on the albums. Not the end of the world, but annoying when, as an example, Van Halen’s Eruption plays after You Really Got Me.

 

Yeah. Ran fine in my '18, my 2020 CRV and now my '23 Tucson. At least the workaround lets me get to the songs eventually. I think the Bose 14 speaker setup has great sound. Far better bass than the H-K in my M4.

 

my USB advances fine with the plus or minus song buttons on the left of steering wheel

if this is a 24, try an infotainment reset, search for the procedure here it’s been written up several times

241LT

 

One more thing to try.
I was using the same SanDisk flash drive in my C7 Vette that was causing an issue in my C8. My C8 Trained Corvette Tech updated the audio software in August 2022 but my problem still existed. He found a note in the GM Service Hits for Audio that said it could be the brand, “Do not use SanDisk USB flash drive with “no reason.” He said it is common for Techs to put notes without reason as it is just what we observed. Bought a Verbatim 16GB Store 'n' Stay Nano USB 3.0 flush mount thumb drive and it solved my problem. The possible reason IMO WHY:
What’s Wrong With The SanDisk Brand That Caused This Issue??
IMO Perhaps Nothing for a Legitimate Card! Funny had a similar issue with my PDR SanDisk SD Card. Others reported similar issues and several blamed it on “Counterfeit Cards” bought on Amazon! I changed that to a Lexan SD Card and the issue was fixed! Frankly in our rural area Amazon is the easiest purchase choice BUT there are always many vendors. One Internet Suggestion to avoid Counterfeits was “ be careful buying from the cheapest vendor!”

Why SanDisk Cards and USB drives may be more vulnerable to cheap copies? My industry experience with one of our strong trademark brand. Heliarc: torches, collet, collet bodes etc, proves the clue. We were by far the market leader back-in-the-day. The company had developed all the many air and water cooled Heliarc Brand TIG welding torches, invented the gas lens etc. These were patented in the 1950‘s and 1960’s. When the patents expired the “copiers” did the logical thing! They copied the high-volume market leader. They often used cheaper materials and less a complex design (as in the case of a gas lens.) But from the outside they looked the same! In our case they did not use our Heliarc name as they can't now! Perhaps the case with “Counterfeit” USB Thumb Drives (flash drives.) SanDisk is probably the Markert Leader, buy a bunch. If you were a part copier what would pick to copy???
Many sellers on Amazon so possible some of those may be selling cheap copies, 2nds, or products that don’t meet the specs that can be sent to the manufacturer. In also appears since mant thinks have to use the same Buss rear speeds may have to be higher. Copies or 2nds sold by some as original could not meet specs. Can’t be sure but in these two cases it worked for me.

 

Make sure you format large USB storage with NTFS. Do not format them with exFAT. The C8 won't mount an exFAT formatted USB storage device.