Looking at your website, that code is working for the blog post title, on the blog item.
This should work for the blog page grid titles:
.blog-basic-grid .blog-title {
font-family: 'Waymar' !important;
}
That code I shared should have targeted the blog title h1, I don't know why it didn't work. You can always try an !important.
.blog-item-wrapper .blog-item-title h1.entry-title {
font-family: 'Waymar' !important;
}