Satellites disconnect, or not able to sync the satellites with the router.
These are some steps you can follow on your end.
1. When the firmware version on the router and the satellite(s) is the latest.
a. Power-cycle the satellites. Unplug the power cable, wait for 10-15 seconds, and plug the power cable back. The satellites will have flashing white light in the beginning, which means it is trying to boot up. The ring LED on the satellites will turn SOLID BLUE after some time, indicating the distance, and the connection between the router and the concerned satellite is good. The ring LED should turn off after that, which means the connection has been established.
b. Now, login to the GUI of orbi router using ORBILOGIN.COM, and check under connected satellites if you the satellites or not.
c. If you do not see the satellites, reset the satellites for 30 seconds and follow the same steps as in a and b.
NOTE: if the light on the satelllites is MAGENTA, it means you need to move the satellite closer to the router. If the light is flashing between magenta and blue, turn off the satellite, and turn it back on.
2. When the firmware version on the router is the latest but not on the satellites.
If you are not able to upgrade the firmware using the GUI of the router, then you will have to manually upgrade the firmware on the satellites. Follow the steps below for that.
1. Login to your satellite GUI. Check the IP address your router recieves. Usually it is 192.168.1.1, or 10.0.0.1(if you have an exisiting gateway connected to orbi router). Now, use the IP addresses in the same range to open interface of the satellites. For ex - 192.168.1.2, or 192.168.1.3 or 1.4. Use the hit and trial method to open the interface of the satellites. If you are still unsuccessful use arp -a command on CMD, and using the MAC address of the satellite(you will find it on a sticker at the back of the satellite) to check if you can see the IP address assigned to the satellite.
2. Use that IP address to open GUI of the satellites. After that go to netgear.com/support and download the current firmware for your downnload. Now on the interface of the satellite you will see the option for firmware update. Browse and select the firmware file and upload it. It will take close to 1-2 minutes. Make sure the format or the extension of the file is .CHK or .IMG.
3. After that the satellites will reboot, and automatically try to connect with the router.