UGS grinds very badly Easel works fine

Hi all,

I have just upgraded my X-Carve to screw drive, the machine seems to be setup well, certainly works fine in Easel. However when I try to use UGS it seems as if it is firing off each step and micro-pausing rather than running a continuous stream of commands. For the life of me I cannot work out why the same machine running the same FW behaves on Easel but not at all on UGS???

Jogging in UGS (failing to do a 10mm jog)

Jogging in Easel (10mm jogs)

Firmware Version: Grbl 1.0c
Easel Driver Version: 0.3.20
UGS Platform v2.0 (build 20200425)

All pots running at 180degs from zero
XY Pots are Off, Off, On, Off
Z Pot is Off, On, Off, On

GRBL Settings
$132=154.000 (z max travel, mm)
$131=800.000 (y max travel, mm)
$130=800.000 (x max travel, mm)
$122=50.000 (z accel, mm/sec^2)
$121=500.000 (y accel, mm/sec^2)
$120=500.000 (x accel, mm/sec^2)
$112=100.000 (z max rate, mm/min)
$111=4000.000 (y max rate, mm/min)
$110=4000.000 (x max rate, mm/min)
$102=50.059 (z, step/mm)
$101=25.000 (y, step/mm)
$100=25.000 (x, step/mm)
$31=0. (rpm min)
$30=1. (rpm max)
$27=1.000 (homing pull-off, mm)
$26=250 (homing debounce, msec)
$25=750.000 (homing seek, mm/min)
$24=25.000 (homing feed, mm/min)
$23=3 (homing dir invert mask:00000011)
$22=0 (homing cycle, bool)
$21=0 (hard limits, bool)
$20=0 (soft limits, bool)
$13=0 (report inches, bool)
$12=0.002 (arc tolerance, mm)
$11=0.020 (junction deviation, mm)
$10=115 (status report mask:01110011)
$6=0 (probe pin invert, bool)
$5=0 (limit pins invert, bool)
$4=0 (step enable invert, bool)
$3=4 (dir port invert mask:00000100)
$2=0 (step port invert mask:00000000)
$1=255 (step idle delay, msec)
$0=10 (step pulse, usec)