I just put an Experience online for test.
Test is good with Edge and Chrome on Windows 10 and Android.
With Firefox, on Windows 10 and Android, the text in the home window is set "Justify" but it is left aligned.
There is a problem with Safari (tests with iPhone 8, iPad and MacBook Air).
Widgets set with a height "auto" appear truncated.
Here is the link to my Experience:
Truncated elements (Image, Text, Feature Info) are on the left part.
Can anyone from the ArcGIS Experience Builder team help me?