From OTRS:
On the page on Function Composition under "Properties" there is a link "[[interval (mathematics)#Infinite endpoints|[0,+∞)]]" which doesn't display correctly on the mobile app[.] As an example the link "[[interval (mathematics)#Infinite endpoints|0,+∞)]]" displays [normally].
Looks like a Parsoid edge case bug. I verified that the MW parser handles this as expected.