Error with connecting over Wifi network

Good day.

I have a problem with connecting Jitsi Desktop XMPP client to openfire over wifi (Unifi).
We have users that’s using for working desktops and laptops. Vlans is used too. Openfire server is in server vlan. Clients with wired connections are haven’t any problems with connection. I’ve add user XMPP account in Jitsi, accept self signed sertificate and all is OK. When I try to connect laptops to openfire over wifi with jitsi in corporate network, i have an error (i create user xmpp account, then there no window where i must accept certificate, instead of this at bottom of right corner i have error: Could not establesh connection for next account:“user@domain”. Check your connection). If I use external internet for connectiong, there is no error and connection is OK.

All settings are simular like desktops. Other XMPP clients working well. But we need jitsi for work. Jitsi logs is empty, Openfire log without errors. Jitsi version 2.10. How to solve the problem?

An answer has been found. For the internal xmpp connection, I use the split DNS function to resolve the external DNS name in the internal IP address. With wireshark, I saw that some laptops, when clients connect to the xmpp server, take an external IP address from the DNS server, and the TCP session is rejected (I do not use hairpin NAT). Then, after a few minutes, they received a valid internal IP address from DNS and the connection with xmpp server was successfully established.

UPD: additionally, I’ve turn off using DNS in Jitsi advanced settings. I think, this is reason, why jitsi taked external xmpp ip address first