Hi,

could you please try to add

#+LATEX_CLASS: beamer
#+LATEX_CLASS_OPTIONS: [presentation,aspectratio=169]

instead of

(require 'ox-latex)

(add-to-list 'org-latex-classes
             '("my-beamer"
               "\\documentclass\[presentation,aspectratio=169\]\{beamer\}
[NO-DEFAULT-PACKAGES]"
               ("\\section\{%s\}" . "\\section*\{%s\}")
               ("\\subsection\{%s\}" . "\\subsection*\{%s\}")
               ("\\subsubsection\{%s\}" . "\\subsubsection*\{%s\}")))

and see if that makes any difference?

My .2cents, /PA
-- 
Fragen sind nicht da, um beantwortet zu werden,
Fragen sind da um gestellt zu werden
Georg Kreisler

Headaches with a Juju log:
unit-basic-16: 09:17:36 WARNING juju.worker.uniter.operation we should run
a leader-deposed hook here, but we can't yet