I use a pln to dwg translation every day. There is no problem just need to understand things. as Mikas said, saving from the model is the direct saving of the working file. While saving from the layout (which I presume is the case here) is another matter.
Namely, when you save from the layout, with the frames and margins set, the layout view also opens in the autocad. When you click the model view (lover left part of the AutoCAD interface screen), there is a "stiffed" drawing that looks like jpg or pdf. This is the way to work with the so-called x-ref files (referenced files). They serve only as a basis, through which it is drawn into the autocad. When you send new x-ref files to colleagues, they only replace them. As an old system of manual drawing and stacking of paus paper one over the other.
You can set the option to send x-ref files or editable drawings in the translator.
AC22 • iMac 3,4GHz Intel Core I5 | 16 gb ram • OSX10.14.4