That’s almost the same as what I’m experiencing. Very interesting of mine is the failure is weirdly consistent and predictable.
Until last night, I changed the ‘triangle’ grid pattern to a bigger hexagon with 1mm spacing of the pattern, it passed the grid print for the first time. But… failed with same issue close to 90%, sadly.
An interesting thing on extruder not sure if its same to everyone own P1 series. Default extruder spring tension seems to be at maximum point the first time I open the extruder, i.e. the screw controls the spring has been set to the tightest point and making spring very ‘squeezed’. Haven’t doubt about it as I was fine printing for the last few months until I saw JohnnieWalkerBR’s first post: P1S Stops extruding mid print