I noticed it takes awhile to connect to public WiFi. When selecting the WiFi in settings said:
I have an XS and the last couple of weeks I have installed the beta, 16C101 and 16C104. I found that when arriving at a particular public WiFi spot the beta would do the same as you described. Would show as connected in Settings, but not in status bar. Apps would not connect until WiFi was established or turned off.
With 16C104, it would cut down the actual connect time (status bar) by at least half.
With 16C101, it connects within a couple of seconds (status bar). One morning it had connected when I woke the phone.
I'm leaving the 16C101 on my XS till the next beta arrives.