Hi,
To add to what IC has mentioned, the "not parsed" errors shouldn’t be a problem.
What could be causing the lack of synchronization between the streams (and the "Back time on rtsp_stream" errors) is a mismatch between the total bandwidth of the input streams and the I/O capability of the network hardware between the EMS and the encoder. You may need to upgrade your network card(s) and/or router(s) to handle the required bandwidth and minimize lost packets.
Cheers,
Don