The infightings might very well have something to do with the ceasefire between the opposition and the government, that Russia, Turkey and Iran negotiated. Even if the ceasefire hasn't hold it at least momentarily eased the fights between these parts and probably have (had) impact on the relations between different opposition groups.
HTS has neverfollowed these ceasefires. I am not sure if Ahrar al-Sham accepted this one, but I think so. Or I am wrong?