I’m having the same issue. Update of the nightly is stuck on the: Date: Jun 12 2023 16:03:36 version. Libraries and 3D models do update when I run system updates, but KiCad itself does not.
paul@cezanne:~$ sudo apt update
...
Ign:25 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 Packages
Ign:26 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main i386 Packages
Ign:25 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 Packages
Ign:26 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main i386 Packages
Ign:25 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 Packages
Ign:26 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main i386 Packages
Ign:25 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 Packages
Ign:26 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main i386 Packages
Ign:25 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 Packages
Ign:26 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main i386 Packages
Err:25 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 Packages
Cannot initiate the connection to ppa.launchpad.net:80 (2620:2d:4000:1::3e). - connect (101: Network is unreachable) [IP: 185.125.190.52 80]
Err:26 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main i386 Packages
Cannot initiate the connection to ppa.launchpad.net:80 (2620:2d:4000:1::3e). - connect (101: Network is unreachable) [IP: 185.125.190.52 80]
...
W: Failed to fetch http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu/dists/focal/main/binary-amd64/Packages Cannot initiate the connection to ppa.launchpad.net:80 (2620:2d:4000:1::3e). - connect (101: Network is unreachable) [IP: 185.125.190.52 80]
W: Failed to fetch http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu/dists/focal/main/binary-i386/Packages Cannot initiate the connection to ppa.launchpad.net:80 (2620:2d:4000:1::3e). - connect (101: Network is unreachable) [IP: 185.125.190.52 80]
W: Some index files failed to download. They have been ignored, or old ones used instead..
And an upgrade shows that footpritns and symbols are updated:
paul@cezanne:~$ sudo apt upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
kicad-nightly-footprints kicad-nightly-symbols
2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 26,3 MB of archives.
After this operation, 293 kB of additional disk space will be used.
Do you want to continue? [Y/n]
Get:1 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 kicad-nightly-footprints all 202310232318+4a50e5d33~14~ubuntu20.04.1 [23,8 MB]
Get:2 http://ppa.launchpad.net/kicad/kicad-dev-nightly/ubuntu focal/main amd64 kicad-nightly-symbols all 202310220921+0a27a187~10~ubuntu20.04.1 [2.569 kB]
Fetched 26,3 MB in 22s (1.203 kB/s)
(Reading database ... 495971 files and directories currently installed.)
Preparing to unpack .../kicad-nightly-footprints_202310232318+4a50e5d33~14~ubuntu20.04.1_all.deb ...
Unpacking kicad-nightly-footprints (202310232318+4a50e5d33~14~ubuntu20.04.1) over (202310102017+b64cd3571~14~ubuntu20.04.1) ...
Preparing to unpack .../kicad-nightly-symbols_202310220921+0a27a187~10~ubuntu20.04.1_all.deb ...
Unpacking kicad-nightly-symbols (202310220921+0a27a187~10~ubuntu20.04.1) over (202310111317+ea20e467~10~ubuntu20.04.1) ...
Setting up kicad-nightly-footprints (202310232318+4a50e5d33~14~ubuntu20.04.1) ...
Setting up kicad-nightly-symbols (202310220921+0a27a187~10~ubuntu20.04.1) ...