When Using the "Set Position in Viewport" it changes anchor values of a widget to 0. This node seems like this should not be changing the anchor values, but it is unsure if this is intended behavior. This issue does not appear to be a regression.
Versions tested: Issue occurs in all versions tested
4.17.2 - CL: 3658906
4.18.2 - CL: 3794801
4.19.0 - CL: 3776583
Head over to the existingAnswerHub thread and let us know what's up.