Internet traffic sometimes denied

Hello all,

I have a little issue with some traffic internet traffic getting denied by my Sophos firewall but I couldn't understand why.

Example 1:

Some traffic from a internal computer to Internet doesn't match anything even if my Internet access rule is like LAN zone, Any host, any service destination any zone, any destination any services (detail of the internet rule below):

Example 2:

Exactly the same kind but some traffic are going through and some others denied. I didn't made any changes between all logs:

Example 3:

In this last example, I see that most of TCP packets are allowed but not UDP.

But my Internet access rule doesn't filter on TCP only:

Internet FW rule details:

Do you guys have any ideas ?

Thanks