button outline disappeared after WP update

After the 5.9 WP update buttons with style outline would not have any border anymore. I found a workaround to fix it temporarily with additional CSS but would be nice to have it fixed in a future theme update.

If you have the same issue, add the following to additional CSS:

.is-style-outline>:where(.wp-block-button__link), :where(.wp-block-button__link).is-style-outline {
border: 2px solid;
}