Cross browser issue adminhtml in Firefox

[TommyKolkman]

Hi!

Magento 2.2.6
MaxServ_YoastSeo 2.0.0
Firefox 62.0

In category, cms and product adminhtml pages, the Yoast SEO block seems to open / close the wrong block. As far I can see, it's only happening on Firefox (my version is 62.0).

Seems like a simple CSS fix, I'm not a front-ender though!