Fitting printed objects

Hi!

Im having some problems trying to print objects that fit together. Previously i’ve made all my holes/cavitys 0.3 mm larger than they should be and it turned out pretty good. Now however something is freaking out. Yesterday I printed a hole and a cylinder, both 6 mm in diameter. But one turned out quite alot smaller and the other one larger.


Read quite alot about what could cause the problem and lots of people are talking about flow. Mine is set to 90% and works fine, im a bit hesitant to change this setting as it seems to cause other problems. The quality of my prints is good so I dont want to “fix anything that isnt broken”. My stl files are set to super high quality, could that cause problems?

Does anyone have an idea how I should go about this? All my settings are standard k8400 single extruder.