scanvideo/mandelbrot doesn't work on a Pico 2; does work on Pico

[jpeter20]

Have been happily using mandelbrot display on a VGA demo base board. Wanted to try on a Pico 2 I bought. I used the methods below to build the code. When mandelbrot runs on the Pico 2, the VGA monitor stays in sleep mode. It appears no valid scan data is getting to the monitor.

I also tried demo1, demo2, mario_tiles, and sprite_demo. They all work using my build methods below, for the Pico 2. It appears to be only mandelbrot that doesn't show anything on the screen.

I made sure all the sources are up-to-date with the latest, including pico-sdk. Here are the build commands I used, on a Raspberry Pi 3 Model B+:

For Pico:

$ cd ~/pico/pico-playground
$ mkdir build
$ cd build
$ cmake ..
$ make -j4 mandelbrot
$ sudo picotool load -v -x mandelbrot.uf2 -f

For Pico 2:

$ cd ~/pico/pico-playground
$ mkdir build2
$ cd build2
$ cmake -DPICO_BOARD=pico2 ..
$ make -j4 mandelbrot
$ sudo picotool load -v -x mandelbrot.uf2 -f

P.S. Just saw the Preview button up there now, sorry for the multiple edits before I found it.