Inconsistent phyXtpt trigger on RE450 v2 - 2.4 vs 5 Ghz

I have setup a new tp-link RE450 v2 with 19.07.6 ( full factory reset ie all options set to default ) and noticed that as soon as I add a second SSID to 2.4 band (phy1) the Wifi Led started to blink at about 5-10 Hz and only stops for a second or two at random points. When I add a second SSID to 5Ghz band (phy0) its Led does not blink ie stays solid on. When I go back to a single SSID on 2.4Ghz Led works as expected.

I experimented with different triggers and looks like phy1tx and phy0tx both show wifi management packets being send out, but when the trigger is changed to phyXtpt there is a difference in how the Leds function. The 2.4G is using Atheros AR9561 and 5.0G is QCA988X and only running hostapd ( no wpad ). I tried hostapd with -dd and did not see any traffic unless I used a client. As well iw event -f did not trigger.

I hope someone can explain the difference and if there is a way to make them work the same - thanks.