Stringing, why happens?

Dear All, my printer suddenly prints parts with stringing. Firstly I think it is because I changed material. But when I change it back it still happens.

I tried change another 0.4 nozzle, no luck. Use a 0.6 nozzle, still the same.

Change heat temperature, no use at all!

My software is uptodate(even I tried roll it back to previous version, no use).

Any idea what part of the machine will cause stringing issue? Thanks.

I am having the exact same problem. No idea yet. I was told to check the connection of the heating element to the nozzle and found it to be fine but now the printer is having warping issues along with the stringing. No idea what is wrong.

stringing is normally retraction issue

Try adjusting the print temperature up AND down in 5-degree increments and see if that helps. I've found you can get stringing on the Cetus if the print temperature is too hot, and also if it's too cool.

You may find it helpful to make a small test print specifically for stringing. I made one that was just two pillars about 20mm apart and 5mm high.