Linux puskom-ProLiant-DL385-Gen10 5.4.0-150-generic #167~18.04.1-Ubuntu SMP Wed May 24 00:51:42 UTC 2023 x86_64

//etc/fonts/conf.avail/65-khmer.conf

 <?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
	<alias>
		<family>serif</family>
		<prefer>
			<family>Khmer OS"</family>
		</prefer>
	</alias>
	<alias>
		<family>sans-serif</family>
		<prefer>
			<family>Khmer OS"</family>
		</prefer>
	</alias>
</fontconfig>