This sounds exactly like the “amount of retractions per length of filament” related heat creep / clogging issue we had solved here. Since Snapmaker did not care to actually rework their flawed design of the “non-full-metal” hotends but relied on hiding the issue by lowering slicer retraction settings until the occurrance frequency of the problem was deemed “acceptable” 
, these are still prone to cause this problem the second you use retraction settings any other printer works fine with.
To confirm, pause the printer as soon as this happens (if you let the printer run on the clog might become too big), wait a minute or so to let the PLA liquify again in the upper end of the heat block, extrude some filament to get rid of the clog and hit resume. The printer should print on then as if nothing happened - until the next clog happens…