You should probably also try to encode the stream being published to Wowza using H264 video codec and AAC or MP3 audio codec.
You can also add the video and audio codec options as well: “-vcodec libx264 -vb 500000 -g 60 -vprofile main -acodec aac -ab 128000 -ar 48000 -ac 2 -vbsf h264_mp4toannexb -strict experimental”