How to reproduce: Open in Safari or iOS Safari. Focus the editor below, type in the second paragraph until the text wraps to a second line, then keep typing on that second line. The second line loses jumps between flush and indented as you type. Typically requires space then text to trigger.

This is the first paragraph. It has no indent (first-of-type). Type here until the line wraps to a second line, then keep typing on the second line to see if the indent is lost.

This is the second paragraph. It has a 2em text-indent. Type here until this paragraph wraps to a second line, then keep typing on that second line. On WebKit/Safari the second line jumps between flush and indented as you type. Typically requires space then text to trigger.