Perhaps anybody of you had similar issues: There is a VSTi on the MIDI-track (in my particular case it's Reaktor, but I think it doesn't matter). Two CCs of my Reaktor synth are "MIDI-learnt" to my MIDI-keyboard. The problem is the following: A MIDI-item is created, I put some notes to it. Then this item is selected by selection and looped during I edit it. But when this loop is "restarted" these two CCs are reset to 0 state (although there are no any CC events in the MIDI-item !). This issue doesn't occur every time, I still can't catch any regularity behavior of this. So, it looks like sometimes on selection loop "restart" Reaper sends some MIDI-command to reset CC to 0. Firstly I thought it could be this setting, but disabling this check-box doesn't help. Then I found JS MIDI Logger plugin. But I can't get any result with it, because it shows that some MIDI-events are arriving continuously ! These are the events on the screenshot below. BTW, is it normally ?! Who generates these events ? In other words, if I have any armed track with monitoring ON - these events are arriving continuously. Perhaps, this is some synchronization events like 1/96 Clock or similar ? Also I've checked if my MIDI-keyboard is in good condition (although it's not too logically, because the CC reset takes place exactly on selection loop "restart"). Anyway, just in case I've check my MIDI-keyboard and all its CCs by MIDI-OX software utility. And there is everything OK with MIDI-keyboard, it doesn't generate any "parasite" MIDI-events (e.g. on the screenshot above or any other). Currently my version of Reaper is 4.5rc13/X64. But I experienced this issue on earlier versions as well, just I can't suffer this anymore. There is a lamp in Reaktor which blinks on any incoming MIDI-event. When this CC reset takes place - this lamp blinks. That means some MIDI-event arrives indeed. But I still can't get a clue how to detect which event exactly and who generates this and why. Any suggestions are highly appreciated, please.

Which CCs are they? >

This is a known issue.

Finally, I was able to catch very good reproducing of the bug ! Look to FM Amt knob (left lower corner) and CutOff knob. Firstly I move it both from my MIDI-keyboard. On the first loop cycle everything is OK, but then you can see what happens when the loop "restarts" on the second cycle. This doesn't happen every time ! What I still can't do is to catch any regularity why and when it happens :(