Viewport (detail view) line is printing why

I have this one file where the viewport line is printing and I cannot figure out why. I tried to make the layer where it is no-print but that does not take effect (other no-print layers do not print). I went back to a previous version of this file and the viewport doesn’t print. Indeed in other files the viewport does not print even if the layer is printing (which is a bit strange, but I can live with that). [I checked if there are lines overlapping with viewports, there aren’t).
Any help would be appreciated, N

OK. Please disregard the message above. Apparently Print Width by object was in default. I have no idea how this could happen to all detail views.
My guess it has something to do with exporting a previous version to DWG and restarting working on it from the DWG file. However, I was not able to quickly replicate that.

Also my claim that the viewport is not printing on other files even when layer is printing is not accurate. Results from the fact (which I did not notice) that the default detail view from rhino is created with Print Width set to No Print and not By Layer. As I am a ByLayer die-hard I just assume everything is always by layer.

Sorry for the confusion, N