Can you elaborate on the problems that you're having?
Let me start with a short answer. Go to the link below to see Service Alerts for Garmin avionics. By reading through these you will be able to get a general idea of whats going on. Also, you will need to consider your equipment configuration to determine which of these apply. My B407 has G500H (and its various subsystems), GTS 800, GTX 330ES, GNS 530AW, and GDL 69A, so several of these apply. This setup is advertised as supporting ADS-B In/Out but I have been told not to hold my breath for this.
Garmin Service Alerts link:
Garmin: Service Alerts
PM me if you want more details.