Yes, I’m on Debian 10.
I tried yunohost tools upgrade system. There are lots of upgrades there.
$ sudo yunohost tools upgrade system
Error: You cannot do this right now because dpkg/APT (the system package managers) seems to be in a broken state... You can try to solve this issue by connecting through SSH and running `sudo apt install --fix-broken` and/or `sudo dpkg --configure -a`.
admin@arkadi:~$ sudo apt install --fix-broken
I tried both apt install --fix-broken and dpkg --configure -a and php7.3-fpm stops both of those processes with the same error 
About the install failing I see this line:
Jan 10 07:27:06 arkadi.one php-fpm7.3[6493]: [10-Jan-2022 07:27:06] ERROR: [pool my_webapp] cannot get uid for user 'my_webapp'
This is complaining about this app I have installed, GitHub - YunoHost-Apps/my_webapp_ynh: Custom Web app with SFTP access I’m not sure how to do anything about it, but it seems to bother php.
I also noticed it wants me to upgrade apps that I haven’t even had installed for over a year: Leed, writefreely, keeweb, monitorix. It’s like Pihole literally took my system back in time?
$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 10 (buster)
Release: 10
Codename: buster
Ok at least I’m still on Debian 10.
Also I had the latest version of Nextcloud installed before this all happened, and now it says I’m back on version 18? 
current_version: 18.0.2~ynh1
id: nextcloud
label: Nextcloud
new_version: 22.2.3~ynh1
The more we debug here, the more confused I get.
Full output of yunohost tools upgrade
$ sudo yunohost tools update
Info: Fetching available upgrades for system packages...
Info: Updating application catalog...
Success! The application catalog has been updated!
Warning: Failed to get label for app keeweb ?
Warning: Failed to get label for app writefreely ?
Warning: Failed to get label for app leed ?
Warning: Failed to get label for app monitorix ?
apps:
0:
current_version: 1.7.7~ynh3
id: keeweb
label: None
new_version: 1.18.7~ynh1
1:
current_version: 0.12.0~ynh1
id: writefreely
label: None
new_version: 0.13.1~ynh1
2:
current_version: 1.0~ynh2
id: transmission
label: Transmission
new_version: 1.0~ynh4
3:
current_version: 1.8.3~ynh9
id: leed
label: None
new_version: 1.9.0~ynh3
4:
current_version: 0.16.0~ynh1
id: searx
label: Searx
new_version: 1.0.0~ynh5
5:
current_version: 18.0.2~ynh1
id: nextcloud
label: Nextcloud
new_version: 22.2.3~ynh1
6:
current_version: 0.96.0~ynh3
id: calibreweb
label: Calibre-web
new_version: 0.96.14~ynh1
system:
0:
current_version: 1:9.10.3.dfsg.P4-12.3+deb9u6
name: libdns-export162
new_version: 1:9.10.3.dfsg.P4-12.3+deb9u10
1:
current_version: 1:9.10.3.dfsg.P4-12.3+deb9u6
name: libisc-export160
new_version: 1:9.10.3.dfsg.P4-12.3+deb9u10
2:
current_version: 1.0.2u-1~deb9u1
name: libssl1.0.2
new_version: 1.0.2u-1~deb9u6
3:
current_version: 4.9.228-1
name: linux-compiler-gcc-6-x86
new_version: 4.9.290-1
4:
current_version: 4.9.228-1
name: linux-kbuild-4.9
new_version: 4.9.290-1
5:
current_version: 2:7.4+76+0~20200511.26+debian10~1.gbpc9beb6
name: php-gd
new_version: 2:8.0+91+0~20211231.40+debian9~1.gbpe2a6c5
6:
current_version: 2:7.4+76+0~20200511.26+debian10~1.gbpc9beb6
name: php-mbstring
new_version: 2:8.0+91+0~20211231.40+debian9~1.gbpe2a6c5
7:
current_version: 2:7.4+76+0~20200511.26+debian10~1.gbpc9beb6
name: php-xml
new_version: 2:8.0+91+0~20211231.40+debian9~1.gbpe2a6c5
8:
current_version: 0.10.0-1
name: python3-toml
new_version: 0.10.0-1+yunohost
9:
current_version: 0.53-1+b1
name: unscd
new_version: 0.53-1+yunohost