Cannot make WebSocket connection without SSL

In my application I’m intentionally using Websockets without SSL (ws://…), but since version 16 Samsung Internet Browser automatically switches to wss://… and expects valid certificate which is obviously not there. It fails to connect with following error:

error
Error in connection establishment: net::ERR_SSL_PROTOCOL_ERROR

I think it is a bug. Is there any reason that it ignores my ws:// connection? Is there any way to fix it?

I’m not using SSL, because our application is intended to work in local/private network. It sets up small web server that is accessed with any web browser from the same private network by providing IP address.

We cannot easily switch to SSL because it causes further problems with self signed certificates. We don’t want to ask our users to install certificates, set up DNSes, etc. They are not technical people.

My issue may be the same as: https://forum.developer.samsung.com/t/is-there-any-method-to-disable-blocking-insecure-websocket-connection-in-version-16/17747

One more thing, it works in any other browser, including those most recent chromium based (eg. chrome 96).