Why my pdf r markdown headings are showing up in page header - r

Question

I am going include a logo in the header part of all my pdf pages.
I have a table of contents in my document as well.
Now when I add commands below I get what I want about the logo, however I also get the #headings in the header parts too. Howcan I avoid showing the heading inside header?
---
title: "my title"
output:
pdf_document:
latex_engine: xelatex
toc: true
toc_depth: 4
fig_caption: true
header-includes:
- \usepackage{fancyhdr}
- \usepackage{multicol}
- \usepackage{xcolor}
- \usepackage{graphicx}
- \usepackage{lscape}
- \renewcommand{\familydefault}{\sfdefault}
- \usepackage[debrief, save]{silence}
- \WarningFilter{fancyhdr}{\headheight is too small}
- \WarningFilter{fancyhdr}{\footskip is too small}
- \usepackage{floatrow}
- \floatsetup[figure]{capposition=top}
- \floatsetup[table]{capposition=top}
- \usepackage{fontspec}
---
\addtolength{\headheight}{1.0cm}
\pagestyle{fancyplain}
\lhead{\includegraphics[height=1.2cm]{C:/Path/to/logo/mylogo.png}}
\renewcommand{\headrulewidth}{0pt}
```{r setup, include=FALSE}
knitr::opts_chunk$set(
echo = FALSE,
message = FALSE,
warning = FALSE
)
```
\newpage
# Cats
cat cat cat
\newpage
# Dogs
dog dog dog
\newpage

Answer 1

To remove the headers title from the header, you can use \fancyhead[RO,RE]{}.
---
title: "my title"
output:
pdf_document:
latex_engine: xelatex
toc: true
toc_depth: 4
fig_caption: true
header-includes:
- \usepackage{fancyhdr}
- \usepackage{multicol}
- \usepackage{xcolor}
- \usepackage{graphicx}
- \usepackage{lscape}
- \renewcommand{\familydefault}{\sfdefault}
- \usepackage[debrief, save]{silence}
- \WarningFilter{fancyhdr}{\headheight is too small}
- \WarningFilter{fancyhdr}{\footskip is too small}
- \usepackage{floatrow}
- \floatsetup[figure]{capposition=top}
- \floatsetup[table]{capposition=top}
- \usepackage{fontspec}
---
\addtolength{\headheight}{1.0cm}
\pagestyle{fancyplain}
\lhead{\includegraphics[height=1.2cm]{posit-logo.png}}
\fancyhead[RO,RE]{}
\renewcommand{\headrulewidth}{0pt}
```{r setup, include=FALSE}
knitr::opts_chunk$set(
echo = FALSE,
message = FALSE,
warning = FALSE
)
```
\newpage
# Cats
cat cat cat
\newpage
# Dogs
dog dog dog
\newpage