Thank you for the detailed report.
If you are trigger the uTrack24 with footswitch why the devcies are connected to the network? Are you using uRemote as well?
Is the problem present when no network connectivity as well?
Are you sync the uTrack24 internal clock to Wordclock or MADI? (menu/clock source)
Is the pre-recording disabled on your devices? (menu/recording/pre-recording –> OFF)