We did have one that did that, and it was at the auger drive, and it was necessary to caulk and tighten a few bolts.
BUT first it was necessary to take off all the sheetmetal above the auger down under the headstock and clean all the coolant out to get at the bolts that needed tightening; the loose bolts were below the waterline when the machine was completely full of coolant.
If your Haas tech did not all of this then maybe the wrong bolts were tightened.
An open mind is a virtue...so long as all the common sense has not leaked out.