If you experience excessive FLTA alerts during landing then it is likely that the FLTA Exclusion Areas Option is turned off in the IFD5XX/4XX.

Let's make sure this is turned on in the USER Options. 





It's a bit hard to pinpoint in the image but the different shade of yellow is the "exclusion area" where the FLTA will suppress it's alerts so as to not distract the pilot during landing. 

Zoomed in on a random airport, the exclusion area looks like this:

If the aircraft position or an FLTA conflict area is anywhere within that exclusion area, the IFD will not generate the typical FLTA caution or warning alerts. At an airport with no known runways, the airport exclusion area is a 1nm radius circle surrounding the airport reference point. For each known runway at an airport, an exclusion area extends 1nm past each end and 0.75nm on each side of the centerline. Therefore, at an airport with

multiple runways, the airport exclusion area comprises the exclusion area for every runway.