Moinmoin,
every remote analysis is to be taken with care. This said and with Bob's information I assume, that the P'08 Arpeggiator is active (is it lit in layer A or B?), which causes Ableton's MIDI start message to start it and make it run at ableton's clock speed.
As Ableton doesn't send any other information, especially no MIDI note number, this could also explain the Arpeggiator playing a "very low note" (C0?), as stated in the first post.
If P'08 Arpeggiator is not needed in the recording process, switch it off (of course
).
If MIDI sync (start/stop/continue/clock) is not needed in the recording process, disable it with the same obviousness! It is always good advice to transmit MIDI intentionally instead of using default presets and to restrict used messages to the necessary minimum.
If MIDI sync and Arpeggiator are needed in the recording process, care for transmitting MIDI sync messages resp. switching on of Arpeggiator deliberately and in time, not initially or implicitly.
Martin