font-weight and font-style not always applied to tspan elements

Use the following steps to reproduce the issue:
1. download attached AIbugreport.txt file
2. replace .txt with.svg (unable to load an SVG file)
3. import the file to Adobe Illustrator
4. open this file in Google Chrome (or any other browser) to visually see the difference

Actuall result: Google Chrome: "quick" is bold; "over" is italic. Adobe Illustrator: Styles are not applied to these words.

Expected result: Google Chrome: "quick" is bold; "over" is italic. Adobe Illustrator: "quick" is bold; "over" is italic