64x32 panels + SmartLEDv4 - strange output

I’ve been trying to get a handle on how to deal with the 4-way garbling on one screen (FM6124 chip) and horizontal banding on another (chips heavily redacted!) when I attempt to run the examples using a 3.2 w/ SmartLED v4.
I have been through the lines on the sketch that are to do with size and depth etc - no joy, so I’m looking for input on where/what to change in the background code.

I have video images here that are not up-loadable to this site as I am a newby!
[Arduino 1.8.13 and associated Teensyduino 1.5.3]

Hi, I upgraded your trust level, so next time you should be able to upload videos. As I mentioned on Facebook you want to use the latest teensy4 branch (even though you’re on Teensy 3) and the MultiRowMapping example sketch which has instructions in it. You can post back here to get help as needed. There’s no mapping for 32 row MOD8 panels yet, so you’ll have to use that sketch to reverse engineer your panel and get it to work.

Thank you Louis - that’s appreciated.