If you have ADS-B weather radar data on (which it looks like you do), those Blue "X" markings are where the ADS-B data hasn't loaded or downloaded yet.
Either you're too low without good enough ADS-B reception or it's slowly downloading. Just fly a bit higher or wait longer. It all eventually loads.
I've noticed my Sport EX only loads out to about 300nm. Good enough I suppose... But I found I wish it went out further on my really long XC trips.