This is from TeamViewer. Whomever built the .deb and .rpm packages incorrectly included their internal repository address, instead of the public external repository.
apt, zypper, yum, & etc. will fail as this is not resolvable outside of the TeamViewer internal network. At least for OpenSuSE, this repo is listed as 'tvinternal.repo'.
I went to the TeamViewer website and just downloaded the latest .rpm package, then uninstalled the old one, and installed the newly downloaded rpm package.
{21}# rpm -e `rpm -qa | grep teamviewer`
Removed /etc/systemd/system/multi-user.target.wants/teamviewerd.service.
Clearing assignments ...
done
warning: /etc/zypp/repos.d/tvinternal.repo saved as /etc/zypp/repos.d/tvinternal.repo.rpmsave
{22}# rm /etc/zypp/repos.d/tvinternal.repo.rpmsave
{23}# zypper -v in ./teamviewer-suse_15.5.3.x86_64.rpm
...
{24}# ls /etc/zypp/repos.d/t*.repo
teamviewer.repo
Now updates work as expected.
HTH.
--PSK
http://LnxRelease-02/deb
?curl -s https://updates.signal.org/desktop/apt/keys.asc | sudo apt-key add - echo "deb [arch=amd64] https://updates.signal.org/desktop/apt xenial main" | sudo tee -a /etc/apt/sources.list.d/signal-xenial.list sudo apt update && sudo apt install signal-desktop