Vite is adding extra slash / on build url

[foggy cape]

This randomly started happening, today I guess.
This is what's in my layout @vite(['resources/css/app.css', 'resources/js/app.js'])
And this is what it generates (notice the extra slash in front of every url)
<link rel="preload" as="style" href="//build/assets/app-d0649dc9.css" /><link rel="modulepreload" href="//build/assets/app-b877dabc.js" /><link rel="stylesheet" href="//build/assets/app-d0649dc9.css" /><script type="module" src="//build/assets/app-b877dabc.js"></script></head>

I tried to upgrade to Laravel 10 today, then reverted. That might have done something, but not sure what.