I am sorry, but it is not working on my side , either at R81.10 not R80.20.25 (SMBs) :
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FW Monitor SuperTool
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Add host IPs (leave empty for any): 8.8.8.8
8.8.8.8 OK
Add ports (leave empty for any): 53
53 OK
Add protocol (tcp, udp, icmp):
any OK
Capture to file (leave empty for stdout):
Output to CLI
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Executing ? fw monitor -T -F "0,0,0,0,0"
Ctrl-C...
Expert@HDHI220B1FW01:0]#