So, ignoring a Congressional Subpoena is not grounds for impeachment?
Nor is ignoring a Congressional mandate for a "de nuvo" (or whatever it was called - sorry about the spelling here) trial to take place?
Man, if that ain't grounds for impeachment, I sure don't know what is.
You are correct. You don't know what is.
Since you don't know what de novo means or understand that the Congress has no power to order the courts to do anything you don't understand what happened.
All it could do was expand the courts' jurisidiction so that they could consider a case typically outside that jurisdiction. Thus, it had the constitutional power to vote to allow the district court jurisdiction even though it was a mistake to do it. However it could not tell them How to do it or demand anything of it.
I am not sure about exactly what that "subpoena" meant but whatever it meant it had no bearing on the obvious lack of Congressional authority to impeach a local judge. Congress could vote for contempt of Congress for ignoring a legitimate subpoena. Perhaps a review of the Constitution would clarify your misunderstandings about Congress' powers here.