c++ – FFmpeg sws_scale causes heap corruption (Aborted / double free) when writing to QImage

I am developing a video player in C++ using FFmpeg and Qt. I am trying to convert video frames from YUV420P to RGBA using sws_scale and store the result in a QImage. However, my application crashes with Aborted (SIGABRT) or double free or corruption at the sws_freeContext line. The first frame often processes, but the second one crashes.
I am requesting AV_PIX_FMT_RGBA in sws_getContext, but the context is being initialized with dst_format = 26. Is it possible that sws_scale is internally overriding the format, and how can I force it to use RGBA to match my QImage format?

ffmpeg version n8.1.1

The terminal output shows a critical heap corruption error: corrupted size vs. prev_size.
this is swsCtx: enter image description here

Code:

while (av_read_frame(formatContext, packet) >= 0)
{
    if (packet->stream_index == videoStreamIndex) {
        if (avcodec_send_packet(codecContext, packet) == 0) {
            while (avcodec_receive_frame(codecContext, frame) == 0) {
                // FRAME LOAD

                QImage image = renderFrame(frame, codecContext);

                sentToSink(image, sink);

                av_frame_unref(frame);
            }
        } else
            qDebug() << "Couldn't send packet";
    }
    av_packet_unref(packet);
}

QImage MediaPlayer::renderFrame(AVFrame *frame, AVCodecContext *codecCntx)
{
    SwsContext *swsCtx = sws_getContext(frame->width, frame->height, (AVPixelFormat)frame->format, frame->width, frame->height, AV_PIX_FMT_RGBA, SWS_BILINEAR, NULL, NULL, NULL);
    
    QImage image(frame->width, frame->height, QImage::Format_RGB32);

    uint8_t *dest[4] {image.bits(), nullptr, nullptr, nullptr};
    int destLinesize[4] {static_cast(image.bytesPerLine()), 0, 0, 0};

    sws_scale(swsCtx, frame->data, frame->linesize, 0, frame->height, dest, destLinesize);

    sws_freeContext(swsCtx); // Crush occurs here

    return image;
}

void MediaPlayer::sentToSink(QImage &image, QVideoSink *sink)
{
    QVideoFrameFormat format(image.size(), QVideoFrameFormat::Format_RGBA8888);

    QVideoFrame frame(format);

    if (frame.map(QVideoFrame::WriteOnly)) {
        memcpy(frame.bits(0), image.constBits(), image.sizeInBytes());

        frame.unmap();
        sink->setVideoFrame(frame);
    }
}