I encountered this problem too before. Though I just tried adding the Tailwind Prettier plugin to a new Remix project and everything seems to be working. Here are the steps I performed:

1. Installed Tailwind npm install -D tailwindcss postcss autoprefixer concurrently

2. After finishing all the steps outlined in the link above, I ran npm install -D prettier prettier-plugin-tailwindcss

I don't have a prettier config file in place. I'm able to run Prettier through vscode and I can confirm that the Tailwind classes are automatically sorted.

I tried everything but after following the plugin's documentation etc, the only thing that worked for me was putting the "prettier-plugin-tailwindcss" at the end (IMPORTANT) in the array, the order matters. (I had another plugin), the end result looks like this:

I'm also using "twin.macro"

.prettierrc

{
    "plugins": [
        "prettier-plugin-organize-imports",
        "prettier-plugin-tailwindcss"
    ],
    "tailwindConfig": "./tailwind.config.ts",
    "tailwindAttributes": ["tw"],
    "tailwindFunctions": ["tw"]
}