Two regular problems with highlight in IOS
1. Highlights disappearing about a second after they are applied. I often highlight a section in yellow and then overlay parts of it in orange For added emohasis. About 50% of the time the orange highlight disappears about a second after being applied. This is a new problem - I have only encountered it very recently.
2. Sometimes when selecting resource text, the black Popup menu simply does not appear at all.
im working on an iPad Pro 2017 on iOS 11.3.1