enter texts doesn't work in a formula bar after clicking a chart

Steps to Reproduce

1. load the attached xlsx with Chrome simulated device, iPad Mini
2. select A1
3. enter a in the formula bar
4. click the chart to focus on it
5. focus the formula bar, enter b

Current Result

A1 doesn't show ab, just a

Expected Result

A1 should contain ab

Debug Information

only happen in a mobile browser, e.g. iPad 15, Safari