Did you drill out the rim? The hole the valve passes through needs to be enlarged. Only on the inner wall (where the tire bead sits) and not the outter (where the spokes enter the rim).
Also, Kenda's tend to be a pain to use tubeless. The sidewalls are really thin, but that shouldn't affect getting the bead set.
FYI - the Stans kits are a massive PITA to set up in my experience. BUT, once it's set up, it's well worth the effort.
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