Problems Registering/Integrating Widefield Frames

Hello,

I recently downloaded and requested a trial license for APP. I'm working on a couple different images - one of the Veil nebula at 135mm, and of the Deneb/Sadr region at 50mm. Both of these images are done with a Canon t3i and tracked (not guided) with an iOptron Skyguilder Pro.

The issue I'm having is that if I integrate 10 or fewer frames, the integration looks ok. However, if I integrate 20 or more frames, I get serious banding in the image, with various features "repeated" across the frame. It's almost like the image is being sliced up and rearranged incorrectly. I've done this with all default settings in the software, and with LNC/MBB. Both data sets, 10 frames stack ok, but the full data set (49 for the 50mm set and 120 for the 135mm set) does not integrate correctly.

The 135mm data set was taken with a vintage 135mm Asahi Super Takumar f/3.5, and has some CA and poorly shaped stars in the corners. Stars in the center of the frame look ok. The 50mm data was with a newer Canon 50mm f/1.8, and also has some wonky stars in the corner of the frames.

Let me try to upload some downsized photos...

Here's a stack of 10 frames at 135mm of the Veil nebula. I can pick any 10 random frames and they seem to stack fine.

Here's a stack of all 120 frames. All default settings except I enabled LNC and MBB during integration.

Here's a single frame of Deneb/Sadr at 50mm:

Here's a stack of all 49 frames with all default settings in the software:

I'm at a bit of a loss, as I've tried adjusting various settings in analyze stars, registration, and integration with no improvement. Every time it seems to stack correctly when I use a small number of frames, but starting at ~20 frames I start getting these strange artifacts, up to a completely unusable image with all frames stacked.

Sorry for the long post, and thanks in advance for any help you can provide. I'd really like this software to work for me!