[CWBRN-33967] Problem with arpeggio automation

I needed to use the arpeggio in a recent project.  I applied it to Lounge Lizard, and used automation to turn it on during the last two verses of a song.  The first two verses didn't require it.  I used write automation to record the on/off switch and played the song from beginning to end disabling and enabling the arpeggiator at the right spots.  The problem is that when the focus is on another track, not Lounge Lizard, the arpeggiator doesn't work 100% of the time.  It works OK when the focus is on LL, but only about half the time when I'm focused on another track.  Yes, the read automation button is on, and I've used automation before successfully.  And, this is not a simple instrument track, but a split MIDI track and audio track.  The automation is applied to the MIDI track.  I've read the manual and can find no reason for this behavior.  Has anyone else seen this, and if so, is there something I'm missing?  Thanks in advance for your time and answers.

Thank you, Anton, for taking the time to reproduce this.  Maybe others will see this, too.