I’ve been trying to troubleshoot and ask around so I appreciate anyone’s help in advance.

I have a 2014 MacBook Pro. 256 gb w 8 gb of ram. Mojave and the most recent Pro DJ. I use a Pioneer S9, two Technics and Phase now for the past two months.

I DJ mostly weddings and corporate events. During cocktail hour this past weekend I noticed it sounded like someone was adjusting the pitch at certain points of the song. It played fine internal mode. The songs would just take off with bpms ranging seeming to be plus 10 but not showing on the computer. Even +/- 2 changes would take a long time to show on the songs display. I switched out to needles, records swapped and then switched to my backup computer. I restarted the original one with no luck. Everything worked fine with the backup computer. No issues whatsoever.

There were no physical or visual signs with the computer (ex: heat, alerts in Serato). Am I missing something obvious? It would seem to me that signs point back to the original computer.

I appreciate any help.