I too have have additional Command Failed messages of late and have added additional things to my network. However, I periodically reboot all my prontos as well as my extenders.

To reboot the Pronto, hold simultaneously Home + Menu + Page Plus.

Find out what got added to your network recently that could be causing more UDP traffic.

Also, you did not tell us type of RFX , RFX and Pronto firmware revisions, and your usage mode. For example, RFX9400 can be used in standalone or network mode. If this is an RFX9400 in standalone mode, when was the last time it was rebooted? The RFX9400 in standalone I've seen performs better with a reboot every now and then.