Hi, thanks for your help! Update: the problem somehow solved itself. The combined CSS files do not show up as render-blocking anymore. Before that I also compared the waterfall charts from GTmetrix from before and after the updates and the position and loading time of the combined CSS files were the same. I can’t see why they were flagged as render-blocking. It seems like the real problem are some new Google Fonts and some JS files which weren’t there before. I guess they come from the WP update or other plugin updates. The size of my homepage went from 1.32 MB to 1.75 MB and instead of 57 requests there are 82 now, but that has nothing to do with Hummingbird.
Update: Somehow I got it to combine the files correctly for both versions – desktop and mobile, but the combined CSS file still shows up as render-blocking which it didn’t do before the update to WP 5.5.
