RX65e detection quesiton

I've bought an 65e yesterday (yeeey 8) ). I live in Romania and as i have read from one topic here only K band radar (24.15) is used in my country.
But as i droveyesterday through the city it detected Ka band a couple of times at random freq. What could trigger such an alarm.

And should i worry if it detects frequencies near 24.15...for example it detected 24.147 a couple of times about 5-10 seconds with weak signal or it must be exactly 24.15 for it to be radar.

Will atop the dash affect the rear detection ability ? It's now mounted in the center of the windshiled between the 2 car seats but is very visible from behind.