When there is a absolute-positioned css grid, it's children aren't growing to fill it. Minimal test case: https://codepen.io/Cactucs/pen/bjKGeX should show green page as in Chrome or Firefox. Instead it is red. (Possible userland workaround is to make it into two elements as shown here: https://codepen.io/Cactucs/pen/GBGRya) Tested in Browserstack on varios versions of safari (both desktop and mobile, including Safari TP) and Webkit Nightly.
*** Bug 213281 has been marked as a duplicate of this bug. ***
Another example from bug #213281: * https://twitter.com/geddski/status/1243292506793463809 * https://codepen.io/geddski/pen/ZEGmwQr
*** This bug has been marked as a duplicate of bug 204578 ***