SGI not working

RB493G /w R52nM PCI card
ROS v6.37.5

When using 2.4GHz on the R52nM radio I’m not able to get SGI speeds. If I change the R52nM radio to use 5GHz, SGI works.
I’m using a Mac Mini /w Broadcom BCM43xx wireless 2.4/5GHz. Also my mAP lite has same issue when connecting to the RB493G + R52nM.

However if I turn off the RB493 & change the mAP lite from station to AP, the Mac Mini and the mAP lite will negotiate SGI speeds over 2.4GHz. All my wireless settings are identical on the mAP lite & RB493. So the Mac Mini connecting to the mAP lite works with SGI on 2.4GHz, but not when connecting to the RB493 as the AP on 2.4GHz. Both routerboards are using the same ROS.
The only difference I can find is that they are slightly different Atheros chipsets. AR9200 / AR9300.

I’m not using CAPs.
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Have you tried 6.39 ?

It fixed SGI issues we were having.

Thanks,

I’ve tried 6.39 & 6.39.1 and got the same issue. I believe the recent SGI fix was related to CAPsMAN. This might be a separate issue. Or just an incompatibility. Not sure.