Wndr3700 v1 5 GHz txpower limited to 17 dBm

The kids have been complaining about 5 GHz wifi performance since I upgraded to 19.07/19.07.1. Looking into it, I see that while iw phy1 info shows max power ranging from 20-24 dBm, it's getting clamped to 17 dBm. The router is in the US, running the ath79 generic image OpenWrt 19.07.1 r10911-c155900f66 / LuCI openwrt-19.07 branch git-20.029.45734-adbbd5c.

Is this expected behavior? If not, what can I do to fix it?

Thanks.

I get 24 dBm on channel 52 with the same router