I just wanted to add that this bug does NOT only occur with PPAs. We frequently experienced it when downloading (many) package files from the regular Ubuntu repositories.
It seems like this bug got introduced in Apt-Cacher NG 3.7.x, because switching our Apt-Proxy to Debian 11 (which has Apt-Cacher NG 3.6.4) fixed the problem for us.
I just wanted to add that this bug does NOT only occur with PPAs. We frequently experienced it when downloading (many) package files from the regular Ubuntu repositories.
It seems like this bug got introduced in Apt-Cacher NG 3.7.x, because switching our Apt-Proxy to Debian 11 (which has Apt-Cacher NG 3.6.4) fixed the problem for us.