Official SEOW

A few weeks ago an enemy plane showed up on the drop down roster at an airbase(units detected within 2km).
Now another has shown up at another base.

How did it get there?
How bad is this in respect to intelligence?

Just today I couldn't get into the mission planner. It would just kick me back to the sectors page when I try to login.
I had to make the site a trusted one and lower the security level (med-low I think).

Nope, no mods at all. Bone stock game.
I thought everything would be fine as I flew one of the first Crete missions with no issues.