VBA http request impossible with avast

Hello,
I developed a Word application (VBA) that is placed in the Start folder. So it works perfectely in Word and is recognized as secured.
Problem : the program connects to an internet server to get the date of the day and to check the licence. And Avast does not it possible, program generates an error if avast is activated. What should I do ? I need to distribute this program.
Does if I buy a certificate (Thawte) to certificate my VBA code, avast will allow this request. I am not sure because the request does not allow to identify the >VBA program file.
Thanks for your help
Mikael

As you’re a developer, read here:

https://www.avast.com/faq.php?article=AVKB229
https://www.avast.com/faq.php?article=AVKB228