RUT241 and shelly Cloud

Dear,

i have a shelly I4DC connect via wifi to a RUT241.

The connection to the shelly cloud is unstable, sometimes it works for a day. Then it keeps resetting every 5 seconds. Below is the output on the shelly diagnostics, on my home network the shelly is connecting to the cloud without any issue.

I already checked a lot of configuration option in the teltonika but cannot pinpoint where the problem is situated, are their any ideas about which settings might influence the connectivty to the shelly cloud?

shos_http_client.cp:656 0x3ffde994: Finished; bytes 300, code 101, redir 0/3, auth 0, status -7: WebSocket connection closed (0 )

The websockets keeps closing with the above error.

Brgds,

Rik