Have you run any cleaning filament through your extruder? It could have a bit of melted pla lodged in there somewhere that could be causing snags if your filament tolerance is off a little (ie in wider spots). The same variation in filament diameter could be causing just enough friction to stop your print, this happens to me often at lower layer heights. For example, I can print pla all day at 200C at .2mm but 205c or higher must be used for .1mm with the exact same filament and STL. I am no engineer, but I believe the higher temperature makes the filament softer and allows it to flow through the nozzle easier preventing the grinding issue you are experiencing.

TL;DR: try increasing temps by 5-10c or running some cleaner filament through