I've installed unifi controller sw on my Pi4 and managed to start the service, but when I connect the Pi via Ethernet cable to the switch, there is no internet connection. When I connect Pi directly into the ISP modem (It has 4 ethernet ports) the internet connection works, but when I connect it to the PoE switch from UniFi Pi doesn't detect ethernet connection*. The structure of the network is described in the picture but to explain little bit. From ISP there is DSL cable into the modem provided by ISP with 4 ethernet port. From this I've made ethernet connection to UniFi USG modem, leading into PoE Switch from UniFi. The Pi is then connected to switch wit UniFi controller. This setup should work according to my research.
Have I made some critical error in the "network" location of the Pi? What do I miss here?
Is the ethernet port on my Pi somehow bugged and I need to reinstall something?
Do you need more informations?
*FYI: Currently my Pi doesn't have PoE hub, because I have it powered over USB-C. PoE Hub is in plan in upcoming weeks.