Recently purchased a 3-node XE75 (AXE 5400) and a separate single node from Amazon to replace my old Google wifi.

I have AT&T 1Gb service.  With the old Google wifi, I regularly saw 800Mbps download and 700-800 Mbps upload speeds.

Issues: 

1. Since installing the Deco, I am seeing 500 Mbps download speeds and 5-10Mbps upload speeds (via the deco app speed test).  

2. I can't register any of the nodes on the tp-link website.  I keep getting a message which states the serial number doesn't match the country origin even though the serial number has US after it.

3.  Today, the app said there was a firmware update.  I downloaded and installed the update but according to the app only 1 of the 4 nodes updated to the latest firmware (the single node purchase).  The original 3 nodes didn't update.  The app says the network is up-to-date which doesn't really make sense to me since only 1 node is on the latest firmware.

Any help / advice from for the above issues would be greatly appreciated.

Thanks.