Changing the Clip Speed does not adjust the clip in the timeline. This is pretty basic stuff. As you adjust the speed of a clip (via any method), the clip needs to get longer or shorter in the timeline to reflect those speed changes and maintain the clip's In/Out points.
Resolve Studio 15b7 on Windows 10 Pro (1803).
My Biases:
You NEED training. You NEED a desktop. You NEED a calibrated (non-computer) display.