Various Linux distros - SNMP disk OID change

Ubuntu 20.04

sweenig@ubuntu2004vm:~$ sudo apt show snmpd -a
Package: snmpd
Version: 5.8+dfsg-2ubuntu2.3
Priority: optional
Section: net
Source: net-snmp
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Net-SNMP Packaging Team <pkg-net-snmp-devel@lists.alioth.debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 144 kB
Pre-Depends: init-system-helpers (>= 1.54~)
Depends: libc6 (>= 2.4), libsnmp35 (= 5.8+dfsg-2ubuntu2.3), debconf (>= 0.5) | debconf-2.0, adduser, debconf, lsb-base (>= 3.2-13), libsnmp-base
Suggests: snmptrapd
Homepage: http://net-snmp.sourceforge.net/
Download-Size: 56.4 kB
APT-Manual-Installed: yes
APT-Sources: http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
Description: SNMP (Simple Network Management Protocol) agents
 The Simple Network Management Protocol (SNMP) provides a framework
 for the exchange of management information between agents (servers)
 and clients.
 .
 The Net-SNMP agent is a daemon which listens for incoming SNMP
 requests from clients and provides responses.

Package: snmpd
Version: 5.8+dfsg-2ubuntu2
Priority: optional
Section: net
Source: net-snmp
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Net-SNMP Packaging Team <pkg-net-snmp-devel@lists.alioth.debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 144 kB
Pre-Depends: init-system-helpers (>= 1.54~)
Depends: libc6 (>= 2.4), libsnmp35 (= 5.8+dfsg-2ubuntu2), debconf (>= 0.5) | debconf-2.0, adduser, debconf, lsb-base (>= 3.2-13), libsnmp-base
Suggests: snmptrapd
Homepage: http://net-snmp.sourceforge.net/
Download-Size: 56.4 kB
APT-Sources: http://archive.ubuntu.com/ubuntu focal/main amd64 Packages
Description: SNMP (Simple Network Management Protocol) agents
 The Simple Network Management Protocol (SNMP) provides a framework
 for the exchange of management information between agents (servers)
 and clients.
 .
 The Net-SNMP agent is a daemon which listens for incoming SNMP
 requests from clients and provides responses.

Did an snmpwalk of 1.3.6.1.2.1.25.2.3.1.3:

Walking OID 1.3.6.1.2.1.25.2.3.1.3 from ubuntu2004vm.local:161 for version v2c with community=public pdu.timeout=5s walk.timeout=5s
	1 => Physical memory
	10 => Swap space
	3 => Virtual memory
	35 => /run
	36 => /
	38 => /dev/shm
	39 => /run/lock
	40 => /sys/fs/cgroup
	6 => Memory buffers
	7 => Cached memory
	72 => /boot/efi
	73 => /run/snapd/ns
	75 => /run/user/125
	77 => /run/user/1000
	8 => Shared memory

Did a `sudo systemctl snmpd restart`.

Did another snmpwalk of 1.3.6.1.2.1.25.2.3.1.3:

Walking OID 1.3.6.1.2.1.25.2.3.1.3 from ubuntu2004vm.local:161 for version v2c with community=public pdu.timeout=5s walk.timeout=5s
	1 => Physical memory
	10 => Swap space
	3 => Virtual memory
	35 => /run
	36 => /
	38 => /dev/shm
	39 => /run/lock
	40 => /sys/fs/cgroup
	6 => Memory buffers
	7 => Cached memory
	72 => /boot/efi
	73 => /run/snapd/ns
	75 => /run/user/125
	77 => /run/user/1000
	8 => Shared memory

Maybe there's something different about your setup than mine (vanilla ubuntu), snmpd.conf = "rocommunity public". I'm not seeing the shuffling.