M4L devices mess up native arpeggiator

[chapelier fou]

I've discovered that any M4L midi device can mess up the Arpeggiator if it's placed before the Arpeggiator in the FX chain.
I really mean any device. I made a simple MIDI thru M4L device and it makes the Arp act erratically.
I'm not sure why and when it's been introduced, but that's scary.

Simplest example :

- set up a clip with notes every 1/8
- put an arp, Up mode, rate 1/16
You now hear notes at a 1/16 rate.
- drop any MIDI M4L before the Arp.
You know hear notes at a 1/8 with occasional hiccups.

Can you reproduce ?