That's strange, I'm on a similar setup and it works.Ok, it was already at 512 and debug=1 didn't help (it crashes so fast nothing is output).
I did get it to work under a different entrypoint. I used the old the Themehax payload (with just white, blue and red screen) booting to ctrbootmanager, the running homebrew loader 3dsx from there, so technically under SysNAND (mine is also 9.0.0-20E here).
Last edited by danielps,