Edit text results fraction:An existing text which contains number/number (e.g. 33/44) is edited and a space follows after the last number.In text editor the "/" (slash) is automatically changed to "#" (hash key) and results in a fraction in the drawing.
Deactive Fractions optionIn the Text Style in General tab the Fractions option must be deactivated.
https://communities.bentley.com/products/microstation/w/microstation__wiki/17237/multiline-text-spacing-for-stacked-fractions