windows 10 search not working when blocking port 443

Question

So, I was playing with the idea of enforcing a stronger firewall policy by blocking everything by default and only allowing network access for selected applications trough exemption rules.

I figured this would cause some unexpected problems, but I was actually surprised that it affects the (local!) build-in windows 10 search functionality...

After some fiddling around, I figured out that:

• the windows search functionality seems to be broken when it cannot communicate to some microsoft server via port 443 (HTTPS protocol)
• Once it has made its initial connection, I can block network access again; Windows search seems to keep working normally afterwards
• The "search online and include web results" option has been disabled already, so the reason escapes me as to why windows search needs to access the internet to work correctly in the first place... but even so, enabling/disabling this option does not seem to have an effect on how windows search behaves when blocking network access
• Just to be safe I also tried enabling/disabling all other privacy related options, however none seem to have an affect on this windows search behaviour

I wonder if anyone can reproduce this problem? or better yet has a workaround or solution to this problem? Maybe someone with an explanation as to why this is expected behaviour?