Have you tried this with an emacs -q? Your examples work as expected in emacs -q for me.

John

-----------------------------------
Professor John Kitchin 
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803


On Thu, Nov 29, 2018 at 11:58 AM Uwe Brauer <oub@mat.ucm.es> wrote:
>>> "Berry," == Berry, Charles <ccberry@ucsd.edu> writes:

   > I cannot reproduce your export issue with org 9.1.14.
   > You need to provide more details.

Ok, I searched already my custom settings.
   > Perhaps you have a header-arg set that you have not told us about?

   > What does C-c C-v C-i report when point is in each of your source blocks? I get

   > Lang: matlab
   > Properties:
   >    :header-args    nil
   >    :header-args:matlab     nil
   > Header Arguments:
   >    :cache          no
   >    :exports        code
   >    :hlines         no
   >    :noweb          no
   >    :padline        no
   >    :results        none
   >    :session        none
   >    :tangle         test.m


Her is my output

The only difference I can find is the results/replace entry.

Not sure what to do.


Lang: matlab
Properties:
        :header-args    nil
        :header-args:matlab     nil
Header Arguments:
        :cache          no
        :exports        code
        :hlines         no
        :noweb          no
        :padline        no
        :results        replace
        :session        none
        :tangle         test.m