Mwlwifi 802.11w wpa3 issues

About two hours was wasted trying to figure out what became wrong and why Apple HomePod stops playing from iphone:

There are no 802.1X on this network that Learn More link points to.

The problem is that PMF capable devices can't communicate with incapable ones:

The router is linksys_wrt1900ac with openwrt 19.07

I've already opened bug #2890 but like to repeat it here for those who may experience same problem.

The worst thing is that luci (Interface ConfigurationWireless Security) says that 802.11w is supported by mwlwifi but in fact it works bad.