Thanks for your review!
For the issue with "/slabbo admin toggle", it would return "That's not a shop", as you were most likely not looking at a shop.
With the "permissions being broken", according to the support in the Discord, this is due to a belief that the "minecraft.*" permission node would also affect Slabbo, which it does not.
As for the issue of being released for many months, this is just one of the projects I develop on in my free time, and with this plugin being offered for free, I believe that some bugs are to be expected.
I'd be more than happy to fix them when I get the time to do so, but in order for that to happen, I need to know that the bugs are in the plugin, as such, there's a public issue tracker on the plugins GitHub page (see
https://github.com/Sven65/Slabbo/issues) where you can report them.