Horizon had A recall/warning?? Call it what you will. They found that there early RXs would take from 4 to 6 seconds to reboot if the signal was lost for any reason. If you test your RXs by turning off power then turn it back on and it takes several seconds to reboot then they want you to send them your RXs and they will replace them with A new one that boots up in about 1 second.
The warning may still be on there web site. My one student had A lock out and lost his plane. The RX was destroyed in the crash but I had him send it back to Horizon anyway, they sent him A new one and told him to test his other units. His other two had the same problem, he sent them in and now has the new ones.
Horizon took care of this problem in A hurry and the best way they could. Check and be safe.