WLED is nice for 1-dimensional LED strips, or if you don't really care how the animations project on your LEDs, but anything in 2 dimension is painful, the grid mapping in 2D is just overly complicated and obscure. I barely got my simple LED matrix working and I've been doing LED grids with my own software for over 10 years (so I know how easy it can be). WLED was just an awful experience for 2D led arrays or anything more complex than a single LED strip.
Really? I connected four panels to make a display and it was a simple issue of choosing how the panels were laid out.
However, their 2D wizard might be new, so give it a shot if you haven't tried it.
Have you used it recently? The matrix configurator is much improved.