We have 450+ servers (mix of virtual servers 2016/2019 OS)located in the US, and our patch windows have commonly exceeded 5+ hours to complete.  We patch these on a monthly basis. Each month, we also have to manually patch about 30-70 servers manually by RDP.  

How long are your monthly patch windows taking to complete? How many servers are you patching during these windows?   Do you have a mix of virtual servers 2016/2019 OS? How much bandwidth is your pipe your servers use to get out to the internet?  Are you pre-staging (downloading the KB’s ahead of time) prior to the start of the actual patch window? 

In a previous month, we finally found out that we should ignore Beyond_Compare and KB890830 to prevent the update from delaying other items in the manifest.  Still having long windows, regardless of the ignoring of certain apps/KB’s - but we need help to figure out if its in our environment (network, servers, internet, etc).