Tikz font in beamer export - emacs

Question

I'm exporting a presentation from an org file that includes a block of tikz code. This is my minimal working example:
#+TITLE: Beamer Question
#+AUTHOR: J. Doe
#+OPTIONS: H:2 toc:t
#+LATEX_CLASS: beamer
#+LATEX_CLASS_OPTIONS: [presentation, aspectratio=169]
#+LATEX_HEADER: \usepackage{graphicx}
#+BEAMER_THEME: Hannover
#+COLUMNS: %45ITEM %10BEAMER_ENV(Env) %10BEAMER_ACT(Act) %4BEAMER_COL(Col)
* Introduction
** Problem
*** Normal text
:PROPERTIES:
:BEAMER_col: 0.4
:END:
This is how normal text looks; with sans serif font
*** Tikz image
:PROPERTIES:
:BEAMER_col: 0.6
:END:
#+begin_src latex :file tikz.pdf :packages '(("" "tikz")) :border 1pt :results raw % Define block styles
\begin{tikzpicture}[ text/.style={text width=5cm, align=center}]
\node (n) [text] at (0,0) {But if I write text in a tikz picture, it uses the default Latex font (serif)};
\end{tikzpicture}
#+end_src
Exporting this with M-x org-beamer-export-to-pdf produces this slide:
My question is, how can I tell tikz to use the same font as the rest of the beamer presentation?
Things I've tried:
Search online. Found nothing
Export to latex file. The result is that orgmode executes the tikz code, produces a pdf (with the wrong font) and inserts the produced pdf as an image. The problem persists
EDIT: As requested, this is the latex code generated by orgmode
% Created 2020-03-29 dom. 09:45
% Intended LaTeX compiler: pdflatex
\documentclass[presentation, aspectratio=169]{beamer}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage{grffile}
\usepackage{longtable}
\usepackage{wrapfig}
\usepackage{rotating}
\usepackage[normalem]{ulem}
\usepackage{amsmath}
\usepackage{textcomp}
\usepackage{amssymb}
\usepackage{capt-of}
\usepackage{hyperref}
\usepackage{graphicx}
\usetheme{Hannover}
\author{J. Doe}
\date{\today}
\title{Beamer Question}
\hypersetup{
pdfauthor={J. Doe},
pdftitle={Beamer Question},
pdfkeywords={},
pdfsubject={},
pdfcreator={Emacs 26.1 (Org mode 9.1.9)},
pdflang={English}}
\begin{document}
\maketitle
\begin{frame}{Outline}
\tableofcontents
\end{frame}
\section{Introduction}
\label{sec:org689fb7a}
\begin{frame}[label={sec:org3b759e9}]{Problem}
\begin{columns}
\begin{column}{0.4\columnwidth}
This is how normal text looks; with sans serif font
\end{column}
\begin{column}{0.6\columnwidth}
\includegraphics[width=.9\linewidth]{tikz.pdf}
\end{column}
\end{columns}
\end{frame}
\end{document}

Answer 1

The problem is that using a src block causes org to invoke LaTeX on that block and this does not inherit any settings from the document. What if you change begin_src...end_src to begin_export latex ... end_export?