I work for an IT department that's apart of a small company. About a month ago, one of the company employees' started having issues with the extended monitor feature when using Adobe Photoshop and Adobe Illustrator on his new Dell Precision 5520 laptop. The Precision 5520 laptop is hooked up to the TB16 thunderbolt docking station that's also connected to a 27" monitor. When the employee moves a layer in photoshop and then releases the mouse, the image or layer shoots somewhere undesirable and often off the canvas. They said it is not as bad as it was previously but does seem to be getting worse.
As far as troubleshooting,
1) I've updated all drivers and firmware for both the computer and the dock - still didn't work
2) I've tried to replicate the issue on the laptop monitor while using the extended monitor feature - did not happen on the laptop screen. Only happens on the screen selected as the main display
3) I've tried the other screen options such as the duplicate, show desktop 1, etc. - No problems using these options only on the extended monitor
4) I've even tried using a HP x360 1030 G2 to compare and was not able to replicate the issue.