Try working through the Joes Rules to Asking for Help. There are sections on Drive Speed Testings and Network Issues. You can run those and post all the text from the shell window using Preformatted Text (</>) right above where you put text replies. We also need to know what pool and disks you were testing. The other odd item is your listing of MoCA networking. If only Linux and TrueNAS are active on the network we may be okay but otherwise we are sharing everything on that coax cable.