I try to record a with the arpeggiator on, it doesn't record properly, playing all the notes simultaneously at the beginning of the track, then nothing else. This problem is not present with the arpeggiator off.
Without further information on the Arpeggiator settings you are using, the Instrument and Preset you have selected, and how you are playing the instrument ie external MIDI controller or on screen keyboard, it is difficult to advise other than see the installed PDF manual (p50) which is under Help, Documentation
I'm using the on-screen keyboard in version 25.1.2.78. I'm using the revolta synths and every combination of settings for the Arpeggiator produces this issue.