I have this problem using FF ESR when Aguard is on. It is that randomly webpages takes about ten minutes to load. During all that time the status line says "transferring data from local.adguard.com. Reloading the page gives me it immediately. This is especially problematic when filling out surveys or paying for something, since I can't reload the page then. I've had this problem since I had to move from normal FF after version 56.