HA can not connect to ceCONZ anymore

Yesterday I replaced my WIFI router. Since then I am getting the error [pydeconz.websocket] Client connection error in HA.
I am running HA Supervised in a Hyper-V VM and deCONZ on the Win10 host.
Removing and installing the deCONZ integration worked flawless. HA automatically recongizes the gateway and reads all devices. After finishing the setup all entities are unanvailable and I get the above log error.
Is there anything else that I can check?

Check usb passtrough

Why? It has been working fine untill yesterday.

USB dongle passthrough for Hyper-V is not possible without third party apps on host and guest.

The deCONZ app HTTP debug is only showing every 10 seconds:

07:40:08:272 NOTIFY * HTTP/1.1
CACHE-CONTROL: max-age=100
SERVER: Linux/3.14.0 UPnP/1.0 IpBridge/1.26.0
GWID.phoscon.de: 00212EFFFF061107
hue-bridgeid: 00212EFFFF061107
NTS: ssdp:alive
NT: urn:schemas-upnp-org:device:basic:1
USN: uuid:9f348c89-1166-479a-a239-69b622549e84::urn:schemas-upnp-org:device:basic:1

I enabled debug logging for pydeconz, this is what I get:

2021-03-16 12:32:56 ERROR (MainThread) [pydeconz.websocket] Client connection error
2021-03-16 12:32:56 DEBUG (MainThread) [pydeconz.websocket] Websocket starting
2021-03-16 12:32:56 DEBUG (MainThread) [pydeconz.websocket] Reconnecting to deCONZ in 15.
2021-03-16 12:33:09 INFO (MainThread) [homeassistant.components.websocket_api.http.connection] [139725547638304] Connection closed by client
2021-03-16 12:33:11 DEBUG (MainThread) [pydeconz.websocket] Websocket starting
2021-03-16 12:34:09 INFO (MainThread) [homeassistant.components.websocket_api.http.connection] [139725547341856] Connection closed by client
2021-03-16 12:35:10 INFO (MainThread) [homeassistant.components.websocket_api.http.connection] [139725547771408] Connection closed by client
2021-03-16 12:35:19 ERROR (MainThread) [pydeconz.websocket] Client connection error

I installed deCONZ on another Windows machine in the same net for testing purpose and it is working there