Anet A8 - Gaps at circles

[Jan19998]

Hi

since a few weeks or month i have a problem with my Anet A8.
On the printed parts there are gaps at circles, these gaps sometimes go down to the bottom.
At the start of the problem the perimeters of the circles were completely loose.
By now i almost got rid of the gaps but they are still there. But i do not have ideas anymore.
It's mostly the two holes like on the picture. If they are hard to see i will take some more pictures tomorrow.

Maybe some one has an idea how i get rid of them so i can use the printer again.



Anet A8 with .4 mm nozzle, upgraded rods and bearings on the x and y axis (dold mechatronik), many printed upgrades.
Cura 3.4.1 (but the problem stays since a few versions before that)
Red PLA from DasFilament

Heattower printed
Filament measured