Prusa i3 MK3S 3D printer PETG printing problems I am using a new Prusa i3 MK3S 3D printer kit. I print lots of things using PLA and PETG. 

After a week of great performance I noticed that when printing some objects with PETG filament I often encountered a problem  when there's  intense stringing, infill gaps, artifacts, the object sometimes detaches from the plate. I use the Prusa Slicer and Cura and print with the temperature 230/90&nbsp;°C, speed max. 300&nbsp;%.This problem occurs rather regardless of which infill methods I choose. I see this problem more often when printing models sliced with Cura. Sometimes everything goes fine, but most of the time I need to stop the print due to the model collapsing, detaching from the surface, its parts collapsing due to infill gaps. The printer sometimes makes some 'clicking, cracking' sounds when printing with PETG.  My filaments come from Fiberology.

Surprisingly, I have run the selftest, XYZ, Z calibrations and all the other ones without any errors. The wizard told me that the axes are perpendicular and it gave me congratulations. All the other tests went nearly perfect as well. 

I do not encounter any problems using PLA, just with PETG. I try to maintain the filament properly (keep it away from moisture, in a closed box). Sometimes (rarely) I get crashes. The filament often builds up on the hotend and I remove it.

I do not know what to do, the build went very well and there are no errors, even though I am a new user and this is my very first 3D printer. I have searched the web and I haven't found people reporting this exact same thing.

Could You help me? What can I do to improve the quality of the prints, perhaps maintain PETG better (maybe I'm doing something wrong) and most importantly, solve the problem?
230&nbsp;°C is way too cool for PETG and will result in underextrusion unless you print really slow, and poor bonding. Underextrusion in turn leads to stringing because of pressure build-up. I print PETG at 250&nbsp;°C.