Remoter quits while using COMMAND X to cut

[macfaqulty]

I've setup remoter to connect to an older iMac to run iMessage for my work phone.
Having a intermittent issue with CUTTING/PASTING text.
In iMessage on the remote machine it will sometimes kill the connection if I highlight text and then COMMAND X the text to cut it.
Tells me it has disconnected. This is not all the time but a majority of the time.
Any suggestions?

Main Mac Pro is running 10.11.5 and iMac I'm connecting into is running 10.8.5
thanks
Brandon