XDJ-XZ not visible over LAN

Dear community,

I have issues with Rekordbox and "Now Playing 2" software to see my XDJ-XZ, connected over LAN.

Setup:
I have simplified the setup to the basics: XDJ-XZ is connected by LAN cable to simple switch, to which my laptop is also connected (Wi-Fi disabled for the time being).

Testing:
- I have assigned my XDJ-XZ static address, it is normally pingable from my laptop.
- By using Wireshark, I can see packets sent by XDJ-XZ to local broadcast on UDP/50000 in stand-by mode. When I play, it sends also packets on UDP/50001 and UDP/50002.
- I have disabled firewall on laptop, so the packets I see in capture should make it to the application.

Issues:
- In multiple rekordbox and XDJ-XZ manuals and YouTube videos, the setup is easy - you connect both to a switch (or even laptop over wifi, but I have simplified it to reduce points of failure) and the Rekordbox just see the device.
- This is not happening at all. While I can see the packets delivered to laptop, Rekordbox just doesn't move a limb. I tried also other modes than Performance to no avail.
- I came to this observation and issue by using "Now playing 2", where they claim in tutorials I should be able just to open the application on laptop, it will enter Pro DJ Link mode (no other software like Rekordbox needed) and it will just read the packets on network broadcast. This is not happening, the application keeps listening, while periodically detecting whether one of the DJ softwares are On.
- When I open Rekordbox, "Now Playing" detects it, turns off the Pro DJ Link mode, tears down network sockets and then cooperates with Rekordbox ... and since Rekordbox is not seeing my XDJ-XZ, it doesn't do anything.

Tried:
- Reinstall both apps. No avail.
- Rebooting, drivers and stuff. Nothing

I kindly seek someone knowledgeable and technical. Perhaps I just missed something super easy, but according to tutorials and manuals, that shouldn't be the case.

Thank you,

Oldrich