Does standart .net slows the webplayer

I observed a slow down on initialize the webplayer
if i do c# without MonoBehaviour.

I observed it twice doing a standart network class and a simple spline class.
The file was ultra small but the player stucks.

Any suggestions or similar experiences?

The halt is likely the network class you implemented. If it tried to bind sockets or alike during the init it totally locked down the rest.

Wait with network initialization until the rest of the game is fully initialized.