Pioneer DJ REC App stops recording after 6hrs 12min 50sec (4.29GB WAV file size))

Hi, I ran into a really inconvenient issue with Pioneer DJ REC app that stopped recording twice over the weekend. Using an older iPhone (7) that's sole purpose is recording mixes via the REC app, running iOS 15.7.9, over 20GB storage available, recording WAV 44.1, connected to 900nxs2 mixer running latest FW. 

Two nights in a row, the app automatically stopped recording after exactly 6hrs 12min and 50sec. This caused the recording to cut off the last 2 DJ's sets and didn't record anything. The file size for both recordings was also exactly 4.29GB. I know it wasn't a space issue because I still have 10+GB available after the 2 recordings.

Is this a known issue? I've had no trouble recording 4-5 hour sets previously, but this was the first time recording 8hrs or more straight and the app epically failed during the most important times - the closing DJ and second to last DJ sets.