Thanks for reporting this @Cha, we just tested again on our side (both via MIDI Out and USB MIDI), and so far we haven’t been able to reproduce the issue. The automation lane seems to send the expected data even with the Arp FX active.
It’s possible that something in the project or setup might be interfering — perhaps another setting or something specific to the external hardware. If you get a chance, could you let us know if the issue also occurs:
• In a clean, new project
• When connected to a different external MIDI device