Problems with the "Shield Shield" and Relay Shield

Hi all,

I bought a bunch of old protons a few years ago, and with them the Shield Shield and a Relay Shield. I now also have some Argons and some adapters for the Argons to the old pinout.

I have been tearing my hair out because using these shield adapters (which supposedly have 5V level shifting too), I am able to easily control the relays, but when I have been trying to interface neopixels the signals out of these boards are garbage.

If I take my controller out of the shield and connect the pixels on a breadboard, everything is fine. But on these shields the outputs are awful. Connected or disconnected to the pixels, they do not work. Putting a scope on the bare output terminals shows extreme noise and clipped signals.

I’ll have to spin my own adapters, which is fine for now. But can someone tell me what’s wrong here? This was bad for both the Photons and the Argons w/ adapters.