You have a full-metal hotend. These are notoriously finnicky to the temperature transition zone between cooling body and heating block, most especially for PLA of all plastics. A simple way to see if this is your problem, you can replace the existing heatbreak (the part that connects the cooling body to the heating block) by a ptfe lined one. They cost very little. If that solves your problem you know it is this issue and then you can concentrate on solving it and returning to the full-metal heatbreak.

Another possibility is too fast extruding, that is the heating block/nozzle can not melt the plastic fast enough. As raising the temp did not solve your problem, I suspect this is not the case, but I would to see what all your print speeds are.