Write (WR) command fails on SPI

I have code that writes a set of configuration parameters (RE, KY, TO, CE, ID, EE) followed by a WR command. These are all written over the SPI bus. All the commands up until the WR command work fine. I receive a AT command response packets (0x88) with a Command Status of 0=OK. However, when I write the final WR command, I don’t receive the AT command response packet. Instead, I receive an Extended Transmit Status (0x8B) packet which has a Delivery status of Route not found (0x25). Any suggestions why it is failing?

What is the exact part number and firmware version you are working with?

What is the API frame you are sending where the WR fails?

It is a XB9X-DMUS-001 with firmware 900A.

Just now I set out to record the API frame byte-by-byte to report it here to you, and the XBee responded with success. I didn’t change anything, so I don’t know why it’s working now, but I’ll let you know if it fails again, and if so, I’ll post the API frame.