Random Mix on PiCorePlayer

I recently moved my server to a Pi3 running PicorePlayer with the help of good folk on this forum and everything is running good and snappy except RandomMix.

My old server used to start a mix instantly but the Pi server takes about 7 seconds to start playback this is with a library of about 18,000.

The only difference is that I used to use a Custom.Map to send a keypress to start but I've not been able to figure out how to do that on PCP

Any advice?

Thanks
Craig