This problem is fixed with a firmware patch in SSL 360 v1.6.
Download and install SSL 360 v1.6. Go to the SSL 360° HOME page and click UPDATE FIRMWARE on UF1.
Problem (v1.5)
There is a known issue whereby holding/touching the UF1 fader for approximately 25 - 30 seconds continuously causes it to 'freeze up'. It starts resisting movement and therefore stops automation writing. You're most likely to notice this when writing automation. Removing your finger from the fader for a few seconds 'resets' the fader and it starts working again.