_SISSION returns an empty array in PHP

Hi,

Today, after sometime I had to change something in my website.

I havn't touched anything since the last time it was working and now, for some reason, the $_SESSION[..] array returns empty variables.

I did not attach any code since I do not think this is acode issue due to teh following:

• I recently intalled DW 2021 but the problem occurs both in DW 2020 & 2021
• I use xampp as a testing server. Both Apahce & MySQL are woking fine. 
• This only happen whne I try to previw the page using the built in preview funtion in DW.
• It happens both in chrome and edge where the address bar shoes :
  http://127.0.0.1:53154/preview/app/index.html
• It doen not happen on the real webpag (all is woring well)
• It does not happen when I access the web page locally directly (all is working well):
  http://localhost/<mySite>/<myPage>.php

This leads me to think it is a DW/adobe preview issue.
What can I check?