Sry for your hotend. As it leaked before, thats where it was leaking from, most probably through a fissure at that place.
Supposedly the nozzle was clogged or the filament was too hard to push and pressure builds inside melting area, that would be the most fragile point hence it fails at that location. I had exact same point of break some time ago, i concluded it was due to two things. One, i was tightening the thread too hard, and it puts pressure unto the upper part, which could of been sort of avoided if the thermal barrier would of started at an angle, a slope instead a 90 degree. To see that imagine that one would force the thread at room temperature, that would still predictably fail at exact same point. Also, the block had no support on itself, so when the filament is pushing hard into the melt zone, it basically tends to push the block away, which would make again a rupture at same spot because well, that is indeed the weakest point of failure.
Supposedly the nozzle was clogged or the filament was too hard to push and pressure builds inside melting area, that would be the most fragile point hence it fails at that location. I had exact same point of break some time ago, i concluded it was due to two things. One, i was tightening the thread too hard, and it puts pressure unto the upper part, which could of been sort of avoided if the thermal barrier would of started at an angle, a slope instead a 90 degree. To see that imagine that one would force the thread at room temperature, that would still predictably fail at exact same point. Also, the block had no support on itself, so when the filament is pushing hard into the melt zone, it basically tends to push the block away, which would make again a rupture at same spot because well, that is indeed the weakest point of failure.