Hi Betty,
Thanks yo very much for you Answerer.
I do according your suggestion fallowing test's:
Google Chrome on the same Laptop: same result
MS IE on the same Laptop: same result
MS Edge trough a Server where never access this Site: same result
MS IE trough a Server where never access this Site: same result
MS Edge (Private Mode) trough a Server where never access this Site: same result
MS Edge (Private Mode with another Global Account) trough a Server where never access this Site: same result
It looks like it is not the Browser :(.
-Well, actually I have never made this work it trough MS 365 Security.
I get for about a couple of Week another error that MS know this Issue and it is working on it.
Couple of Weeks later, this error disappear but this one comes.
I use before (and I confirm, that's steal working) this feature trough "Office 365 Security & Compliance\Threat management\ Attack simulator".
-No we don't change anything or add any APPs.
-My Account have the Global Administrator role since about two years.
-Also in to other Computer we (me and another Global Account) are getting the same result.
I have also now try with others "Technique" and "Payload" but getting the same result.
Very appreciated for your Help.
Best regards
Mela