Hi,
for troubleshooting purposes (i.e. certificate issues) it is sometimes to enable the debug logging of apt.
This can be done by setting
root@debdev ~ # apt -oDebug::pkgAcquire::Worker=1 update
Or permanently
root@debdev ~ # echo “Debug::pkgAcquire::Worker 1;” > /etc/apt/apt.conf.d/99apt_debug.conf
Michael