Streaky comet in LRGB

I ran an integration on C/2017 K2 yesterday and the result was not what I expected. Sort of the obverse of deep sky stacker's "register stars and register comet" mode, APP produced L, R, G, and B integrations with both the stars and the comet trailed!

I am reasonably sure that this is due to how I interleaved the exposures. Not wanting to end up with big time offsets between the various channels, I had it swap filters with every sub, so the data comprised endless repeats of LRLGLB. When APP prompted me about using timestamp metadata, I clicked "Yes", so the file list window sorted by time, interleaving the channels exactly as shot. I had to click on just about every frame to register the comet -- no big whoop, really. But when I was done I had four streaky integrations.

I tried again, unchecking everything but 14 of the luminance frames, and the comet looks just fine. For that I wound up having to click on about every other frame to register (I clicked "Yes" for "use metadata timestamp" again).

I'm not complaining, or even sure that this is a bug -- it might just be that using timestamp metadata is the wrong choice for this situation. It is, I suppose, somewhat less convenient to select the frames and do the registration four times instead of one. This is more of a "Hmm, interesting behavior" sort of message.