Why does the baseline of a custom font with regular weight vs. semibold differ with 1 px?

When trying to align the text horizontally, they seem to differ in baseline… When I place them within the same textbox, there’s no shift in baseline, but with 2 separate text boxes, it does have a baseline shift.

How can I fix this?

Looks like an issue with the font itself, or maybe you have different line heights set on these boxes.

Both text boxes have the same line-height of 24px, and I checked the same font in different tools such as Word and (sorry) Sketch and there it doesn’t have this issue… So it can’t be the font itself right?

Does it only happen with this font? Which one is it?

Only for this font indeed:
Proxima Nova

Do you have this font in another format? E.g. TTF instead of OFT or vice versa. Try removing the current one and installing a different one instead.