[FS#558] 5GHz interface drops to channel 36 -- DFS?

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Juliusz Chroboczek (jch) 

Attached to Project - LEDE Project
Summary - 5GHz interface drops to channel 36 -- DFS?
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - lede-17.01
Due in Version - Undecided
Due Date - Undecided
Details - I'm running 17.01 on a WNDR3700v2.  The 5Ghz interface is set up to use a 40MHz channel width on channel 60 (5300MHz).  This channel requires DFS in my locale.

Once in a while, the router drops to channel 36; I attribute this to a DFS false positive.  What is more, the router never recovers — it stays on channel 60 until I manually restart the WiFi interface.

I'm fine with the router switching to channel 36 on a DFS false positive — but shouldn't it recover at some point and switch back to channel 60?  I could of course set up a cron job that restarts the WiFi at 4am every night, but that seems like a rather inelegant workaround.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=558