Font-variant-alternates and font-feature-settings not working

Hello everyone!

I use

font-variant-alternates: stylistic(), styleset();
font-feature-settings:   'salt' on, 'ss02' on;

in a few places in my code, and include it in the beginning like this:

<link rel="preconnect" href="">
<link rel="preconnect" href="" crossorigin>

<link href=";200;300;400;500;600;700;800;900&display=swap" rel="stylesheet">
<link href="" rel="stylesheet">

It was working perfectly when I added this code a while back, but at some point it stopped working and I can’t figure out how to bring it back.

The font author suggests to include the font like this:

<link rel="preconnect" href="">
<link rel="stylesheet" href="">

but this doesn’t help. The alternate characters are just not showing up.

What am I doing wrong?