Failed to block test file immediately after boot


I'm using BDTS from version 2015 and since then I make a test with EICAR test file. In first scenario BD passed the test but in second one it failed. The result recur again with version 2017


Scenario 1


First, I switch off on-access scanning until next reboot. Then create a txt file with EICAR string in Windows startup folder. After reboot windows try to open the txt file automatically but BD blocks it even the BDagent icon is still not running in system tray.


Scenario 2


These time I create the same txt file on desktop and reboot again. Immediately after loading of windows I started to open the txt file manually. It continuously open without any problems until BDagent icon show up in the system tray. After that access is blocked again.


I understand that BD load in early stage with OS and protect the PC but why it is possible manually to open an "infected" file.