websocat exits with WebSocketError: UTF-8 failure on a specific line

[alien999999999]

So, i have a python that calls websocat, everything seems to work nicely, for both text and binary, except a specific line seems to trigger a UTF-8 error, but this line does not contain any UTF-8. Is there some automatic unicode converter sequence that i'm accidentally triggering or something weird like that?

( don't worry about the -k , all this is in a locally controlled network vlan)

called from python subprocess:

process = subprocess.Popen([
        "websocat",
        "--text",
        "--base64",
        "--binary-prefix",
        "B:",
        "-k",
        "--linemode-strip-newlines",
        "--protocol",
        "default",
        remote,
        "-",
    ],
    stdin=subprocess.PIPE,
    stdout=subprocess.PIPE,
)

trigger line sent: property set pico-A39B-16.value_type Temperature

error output:

websocat: WebSocketError: UTF-8 failure
websocat: error running

[vi]

Is there a traffic dump (from tcpdump / Wireshark) showing what is happening in the Websocket?

trigger line sent

Send from websocat to the websocket or from websocket to websocat?

[alien999999999]

I did a tcpdump and noticed my websocket server reply was not ok (having 00 in it), my bad.

However, while doing wireshark, is there a way for data to decode as websocket or something? i just had "data" and the part sent by websocat to websocket server was unclear, the other way was visible in the ascii stream.