NextcloudPi - OS Upgrade Procedure?

I’ve been happily running NCP for over a year on a Pi3B and later migrating to a Pi4B 4G. I noticed recently that apt update showed a long list of OS packages that need updating, and was tempted to just issue ‘apt dist-upgrade’ to get everything updated but am hesitating wondering if this is the correct way to update the system. Should I first switch to maintenance mode before I do this?

NextCloudPi version v1.26.2
NextCloudPi image NextCloudPi_03-09-19
distribution Raspbian GNU/Linux 10 \n \l
automount yes
USB devices sda sdb
datadir /data/ncdata
data in SD no
data filesystem ext2/ext3
data disk usage 43G/3.6T
rootfs usage 2.5G/61G
swapfile /var/swap
dbdir /data/cloud
Nextcloud check ok
Nextcloud version 18.0.5.1
HTTPD service up
PHP service up
MariaDB service up
Redis service up
Postfix service up
internet check ok
port check 80 open
port check 443 open
IP 192.168.1.5
gateway 192.168.1.1
interface eth0

uname -a
Linux cloud 4.19.75-v7l+ #1270 SMP Tue Sep 24 18:51:41 BST 2019 armv7l GNU/Linux

I have a rather early Pi4B and have not updated the OS since some of the thermal optimizations were released. I seem to remember seeing some people having troubles with upgrades at the time. Anything I should look out for?

Thanks

There is no need to manually run apt, as long as you have unattended-updates enabled.
https://docs.nextcloudpi.com/en/staying-up-to-date/

Rasbian/Debian 10 (Buster) is the latest and current distro version, so running dist-upgrade, would do nothing.

I do have unattended-upgrades enabled, and it was working fine until March. It hasn’t updated again since then. apt list --upgradable shows 100 updates that haven’t been done yet, including kernel and firmware updates.

I’ve tried examining the logs and haven’t seen any explanation for why updates are not occurring.
Anyone know how often they should be triggered?

You can check apt 's log at
/var/log/apt/history.log

If you do run apt update and (sudo) apt upgrade manually , for some packages, you might get asked if you want to keep the existing config or replace it by a new one. Always keep the exiting one, unless you know what you are doing.