Transport controls on MIDI channels 2-18

[OldDavid]

Using an M-Audio Oxygen 49 MKIV, Reaper 5.9+, on Windows 10, Focusrite Scarlett 2i2, ASIO driver.
Initially, I have two questions about programming and using the Oxygen 49 to work with Reaper.
Using the Actions Menu, I am able to control transport functions on MIDI channel 1 in the ways I expect, but when I switch to MIDI channel 2, where I have programmed the same parameters for that channel, the transport functions toggle on and off or don't work at all. For instance, I have to hold down the RECORD button — the minute I let go recording stops, though the cursor continues on until I hit spacebar on the computer keyboard; the STOP, REWIND, and PLAY/PAUSE buttons don't function at all, though again, they work on MIDI channel 1.
My second issue concerns the Arm Track function. I wanted to program them to toggle on/off with alternate pressings of the keys below the sliders on the Oxygen 49 (labeled C18-C26), but instead of arming the track then unarming it, the track is only armed as long as I hold down the button on the Oxygen 49. This seems to be the same behavior as that of the RECORD button on MIDI channels above one, as described above. Oddly, I have programmed the drum pads on the Oxygen 49 to toggle Arm/Unarm track 1-8, though that's a noisy operation if the microphone is in play.
If I haven't provided sufficient or sufficiently clear information, please let me know. Thanks.