Hello,
I use the kitware apt repository: https://apt.kitware.com/
Just today, I noticed I can no longer run apt-get update.
sudo apt-get update
Get:1 https://download.docker.com/linux/ubuntu jammy InRelease [48.8 kB]
Get:2 http://packages.ros.org/ros2/ubuntu jammy InRelease [4682 B]
Ign:3 https://apt.kitware.com/ubuntu jammy InRelease
Get:4 https://download.docker.com/linux/ubuntu jammy/stable amd64 Packages [49.8 kB]
Hit:5 http://archive.ubuntu.com/ubuntu jammy InRelease
Get:6 http://packages.ros.org/ros2/ubuntu jammy/main amd64 Packages [1632 kB]
Get:7 http://security.ubuntu.com/ubuntu jammy-security InRelease [129 kB]
Get:8 http://archive.ubuntu.com/ubuntu jammy-updates InRelease [128 kB]
Get:9 http://archive.ubuntu.com/ubuntu jammy-backports InRelease [127 kB]
Get:10 http://security.ubuntu.com/ubuntu jammy-security/main amd64 Packages [2458 kB]
Get:11 http://archive.ubuntu.com/ubuntu jammy-updates/universe amd64 Packages [1516 kB]
Ign:3 https://apt.kitware.com/ubuntu jammy InRelease
Get:12 http://archive.ubuntu.com/ubuntu jammy-updates/main amd64 Packages [2753 kB]
Get:13 http://security.ubuntu.com/ubuntu jammy-security/restricted amd64 Packages [3331 kB]
Get:14 http://archive.ubuntu.com/ubuntu jammy-updates/restricted amd64 Packages [3475 kB]
Get:15 http://security.ubuntu.com/ubuntu jammy-security/universe amd64 Packages [1226 kB]
Ign:3 https://apt.kitware.com/ubuntu jammy InRelease
Get:16 http://archive.ubuntu.com/ubuntu jammy-updates/multiverse amd64 Packages [53.3 kB]
Err:3 https://apt.kitware.com/ubuntu jammy InRelease
Certificate verification failed: The certificate is NOT trusted. The name in the certificate does not match the expected. Could not handshake: Error in the certificate verification. [IP: 66.194.253.25 443]
Fetched 16.9 MB in 9s (1798 kB/s)
Others at my company have seen this too on both work and personal machines on different networks.