Thread Border Router (ZBT-2) and iOS: "Thread network credentials does not match with any of the active thread networks around"

@WallyR after spending several hours searching for a solution to my problem, I bumped into this discussion. Could you possibly give me a hand with this very same problem?

I’m using a Fortinet Software Switch Interface, that combines a wired and a wireless network.

My HA instance has IPv6 configured and so have the devices on this network.

and, for example, this is the output that I see on my Mac:

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=6460<TSO4,TSO6,CHANNEL_IO,PARTIAL_CSUM,ZEROINVERT_CSUM>
	ether 36:a6:f8:e7:7f:bb
	inet6 fe80::cac:3a1e:9427:468c%en0 prefixlen 64 secured scopeid 0xc
	inet 192.168.10.4 netmask 0xffffff00 broadcast 192.168.10.255
	inet6 fd66:1086:7b8e:bae4:cbf:c3d9:ef48:ed16 prefixlen 64 autoconf secured
	nd6 options=201<PERFORMNUD,DAD>
	media: autoselect
	status: active

I tried multiple multiple things. I’m at a loss.

I downloaded the app DNS-SD Browser on my iphone, and the truth is I don’t see

__meshcop.udp

as described here

any ideas?