Apple Watch Ultra keeps disconnecting from WiFi

Hello,

while at home and connected to my iPhone, my Apple Watch Ultra does not seem to connect to WiFi.

It does not connect automatically. When I do it manually, it connects to the network just fine but drops it after 10 seconds or so.

it does not happen while away from my iPhone - then WiFi connection is flawless. Tested it in the same house with the same network.

is this an issue or is it a normal behavior of a Watch connected to an iPhone?