Why did/does Tahrir al-Sham fight ISIS?

Both groups are sunni, both oppose Assad as well as Kurdish fighters, as well as Shia fighters.
Is the reason they fought/fight against each other just based on factionalism, or are there meaningful differences in their ideology and what they want to achieve in Syria (and elsewhere?).

Is the global Jihad and caliphate that's advocated by ISIS something Tahrir al-Sham opposes?

Thanks for any insights and/or theories :)