Adjustment on iOS-Devices not correct

[Daniel]

This looks like the minute difference between how browsers determine what to do with the 'auto' property on line-height. This might help:

HTML export increasing letter spacing

Without adjusting these properties, Hype will set attributes for the letter-spacing and line-height properties to be ‘normal,’ and word-spacing to be 0px. So what we’re seeing is the difference between ‘normal’ and 0px for the letter spacing. To tell browsers ‘don’t use the default’, going up then down on line-height and letter-spacing should do the trick as @Rick4F mentioned.

If you set the line height explicitly in the Typography inspector this will likely fix your issue.