What causes this "jumping" between two straight faces?

[lgguts 0]

Image link: https://ibb.co/dxBEva

(sorry, I could not embed it for some reason)

I have tried decreasing speed, layer height, levelling the bed... and every now and then this problem comes back in very simple prints that should have two straight faces close to each other.

This one was printed with an Ultimaker 2 Extended, PLA White, and standard configurations from Cura ("Normal" quality) - to rule out any misconfiguration of it from my part...

Any idea?

Thanks!

[gr5 2,172]

It's called "stringing". I find it is worse with white filament (all brands). One fix is to reduce the pressure in the nozzle by lowering the speed. A lot. Try 20mm/sec as your minimum speed. Also lower temperature. Try 190C on the um2 (but only if printing very slow). Lower on the um3. Also check all the retraction settings. If the gap is small sometimes it doesn't retract but you can change the settings so it always retracts.

But mostly I recommend trying a different color.

[bsilverwood 8]

Looks like stringing...

Temp and retraction values tend to solve this. Verify you are using the proper temps for the material used. Also, ensure you have retraction going on. See the link below:

How to Fix Stringing

[lgguts 0]

Thank you very much for your both answers! I will run some tests and come back if it persists - but now that I know the right name of it and its possible causes, I feel confident.

Cheers!