I don't have a great deal of welding experience, all I can suggest is ensure all points of the weld are calling the same weld data and the correct data for the materials you are welding.
Also make sure you have the correct stick out for the The diameter of the weld tip you are using, example we use 1.0mm weld tips and use a 15mm stick, (stick should consistently be 15mm throughout the entire weld or you will see a visual difference in the weld)
I Would recommend having a play around with the weld speeds and such on the pendant.
Hope some of this is slightly useful for you, and apologies I'm not that experienced myself.
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