On this Dell 15-7568, there is a touchpad with the left and right click areas merged into the pad.
Steps to Reproduce
With a clean install of 16.04:
- Place Thumb on left-click area
- Place middle finger on center of pad
- Click with thumb by pressing down
The pointer no longer moves on the screen until:
- Pace thumb on left-click area
- TOUCH (not press) the center of pad
Pointer movement is back to normal.
- Has anyone else come across similar issues? I'm trying to track down if this is Dell-specific. 
- What other useful diagnostic info could I provide? 
System Information
sudo dmidecode | grep "System Information" -A 3
System Information
    Manufacturer: Dell Inc.
    Product Name: Inspiron 15-7568
    Version: Not Specified
xinput --list
⎡ Virtual core pointer                      id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ ELAN Touchscreen                          id=11   [slave  pointer  (2)]
⎜   ↳ DLL06FF:00 06CB:75C4 Touchpad             id=12   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=14   [slave  pointer  (2)]
⎣ Virtual core keyboard                     id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=8    [slave  keyboard (3)]
    ↳ Sleep Button                              id=9    [slave  keyboard (3)]
    ↳ Integrated_Webcam_HD                      id=10   [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=13   [slave  keyboard (3)]
    ↳ Dell WMI hotkeys                          id=15   [slave  keyboard (3)]`
xinput --list-props 12
Device 'DLL06FF:00 06CB:75C4 Touchpad':
Device Enabled (137):   1
Coordinate Transformation Matrix (139): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
Device Accel Profile (268): 1
Device Accel Constant Deceleration (269):   2.500000
Device Accel Adaptive Deceleration (270):   1.000000
Device Accel Velocity Scaling (271):    12.500000
Synaptics Edges (292):  49, 1180, 50, 4416
Synaptics Finger (293): 25, 30, 0
Synaptics Tap Time (294):   180
Synaptics Tap Move (295):   67
Synaptics Tap Durations (296):  180, 100, 100
Synaptics ClickPad (297):   1
Synaptics Middle Button Timeout (298):  0
Synaptics Two-Finger Pressure (299):    282
Synaptics Two-Finger Width (300):   7
Synaptics Scrolling Distance (301): -30, -30
Synaptics Edge Scrolling (302): 0, 0, 0
Synaptics Two-Finger Scrolling (303):   1, 1
Synaptics Move Speed (304): 1.000000, 1.750000, 0.129870, 0.000000
Synaptics Off (305):    0
Synaptics Locked Drags (306):   0
Synaptics Locked Drags Timeout (307):   5000
Synaptics Tap Action (308): 2, 3, 0, 0, 1, 3, 0
Synaptics Click Action (309):   1, 3, 0
Synaptics Circular Scrolling (310): 0
Synaptics Circular Scrolling Distance (311):    0.100000
Synaptics Circular Scrolling Trigger (312): 0
Synaptics Circular Pad (313):   0
Synaptics Palm Detection (314): 0
Synaptics Palm Dimensions (315):    10, 200
Synaptics Coasting Speed (316): 20.000000, 50.000000
Synaptics Pressure Motion (317):    30, 160
Synaptics Pressure Motion Factor (318): 1.000000, 1.000000
Synaptics Resolution Detect (319):  1
Synaptics Grab Event Device (320):  0
Synaptics Gestures (321):   1
Synaptics Capabilities (322):   1, 0, 0, 1, 1, 0, 0
Synaptics Pad Resolution (323): 12, 12
Synaptics Area (324):   0, 0, 0, 4000
Synaptics Soft Button Areas (325):  614, 0, 761, 0, 0, 0, 0, 0
Synaptics Noise Cancellation (326): 7, 7
Device Product ID (255):    1739, 30148
Device Node (256):  "/dev/input/event14"

 
     
    