after upgrading to 2.4.43 httpd stopped serving requests given IP number rather than domain name
This is a really surprising and unlikely behavior. At least you should provide some additional information (configuration, log file, ...) With just your description, we can hardly do anything.
I did nothing else but upgraded to newer version of httpd. All configuration remained the same and worked before. The configuration has 1 vhost and looks like <VirtualHost IPNUMBER:80> ServerName HOSTNAME ServerAlias IPNUMBER ... I tried several variations on this. request http://HOSTNAME works fine, request http://IPNUMBER accepts connection, but after sending request it stills. I can see TCP connection, but httpd seems to do nothing, nothing appears in logs. If you have any suggestions for obtaining more information, I can try it.
What other information should I try to provide?
This works for me. Could you share more of your configuration or try to have a minimal one that reproduce your issue? Do you have anything in your logs?