That's really confusing. I did that exactly with Atmosphere's latest base and it did nothing.
I just did Kosmos to see if that'd fix it (first I'd heard of it)
Kosmos lets it boot and do...something. Sept comes up, it flashes some dialogue quickly and then my switch shows the NINTENDO logo. After that, the logo fades out and my Switch stops responding to anything...
did you get the latest release of kosmos? I know the first one was buggy
With the latest atmosphere, I copied everything onto the sd card and launched fusee-primary through hekate 4.6, dunno if that will help