Glitch in PETSCII rendering

[sblendorio]

Hi uploaded and configured VTXClient at this URL:
https://www.sblendorio.eu/vtx/

You can try interacting with it: sometimes chars are rendered, but most of times no, only blank space in place of every char.

The "reference" output is here (it's a full C64 emulation):
https://bbs.retrocampus.com/

Websocket is at wss://bbs.sblendorio.eu:8080
Corresponding "vanilla" socket is at bbs.sblendorio.eu:6510

Those are parameters I used in index.html:

    var vtxdata = {
        sysName:        "Retrocampus BBS online",
        wsConnect:      "wss://bbs.retrocampus.com:8080",
        term:           "PETSCII",
        codePage:       "C64",
        autoConnect:    0,
        telnet:         1,
        wsProtocol:     'bbs',
        wsDataType:     'arraybuffer',
        fontSize:       '24px',
        fontName:       'UVGA16',
        crtCols:        40,
        crtRows:        25,
        crtHistory:     25,
        xScale:         2,
        initStr:        "",
        defPageBorder:  232,
        defPageBG:      0x10,
        defCrsrFG:      0x07,
        defCrsrAttr:    [ 'thick', 'horizontal' ],
        defCellFG:      0x07,
        defCellBG:      0x00,
        defCellAttr:    []
    };
</script>

[sblendorio]

BTW... I noticed that switching from full-screen to non-ful-screen and vice-versa, "lost" characters appear, so it seems to be a refresh issue