Retrieaval of a web page with url-retrieve-synchronously takes considerable amount of time when it's first request for this page or long time has passed since last request of it.  Requests that follow in some interval of time are fulfilled quick.

 Such problem is not expirienced with any other software.  Also no diffirence if the page was requested via other software before url-retrieve-synchronously was called.

 

GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.18.9)