Remote WR command locks up remote DigiMesh modem until it is power cycled.

“Function”: XBee Pro DigiMesh 2.4
Firmware Version: 8073

I have been trying to set the channel number of remote devices using remote AT frames, i.e. 0x17 type frames in API mode. Having had many problems with many combinations of remote CH, WR, using the “apply changes” flag, and AC itself, I settled on doing the following:
Send remote CH without the “apply changes” flag;
Send remote AC;
Put the local modem on the new channel;
Send remote WR without the “apply changes” flag;

I was finding that very often (but not every single time) no acknowledgement was received back from the remote modem when the remote WR command was sent. Since then, I’ve done further testing using X-CTU. I find I can happily send many remote AT commands (PL to get the power level, PL to set the power level, AC) and all works well until I send a remote WR. Sometimes “Status OK” is returned, but very often no response is received. Then when I send any remote AT command, a status of 0x04 “TX failure” is returned. This continues until I power cycle the modem by removing it from the board and replacing it.

I’ve not seen any pattern to when the remote WR command fails and when it succeeds.

The configuration for the local and remote modems are the same except for the Node ID. It is:
C
7255
3
0
3
0
0
0
5
2
3
0
0
T307 Hub
82
2
11
0

3
0
3
BE
1
0
2
0
0
0
0
0
0
1
0
0
0
0
0
BF
0
0
0
28
0
1
0
1
0
1
C8
1388
0
2B
64
3E8
1

TIA,
Graham