1. Use Artboard Rulers

1. Use Artboard Rulers

First of all make sure your Rulers are set to Artboard Rulers. Go to View > Rulers and if you see 'Change to Global Rulers', than you're currently already using the Artboard Rulers, which means each Artboard uses its own rulers. Most importantly, this means that the pattern will stay in place in case you move the rulers' origin point. Also good to know is that in case you've accidentally moved the rulers' position, that you can reset its origin point back into place by double clicking the rulers' top left corner.

2. Transform Patterns

2. Transform Patterns

To resize a pattern within its object, you have to make sure that Transform Pattern Only is selected in the Transform panel/window. To move a pattern's position, go to Effect > Distort & Transform > Transform..., and use the Horizontal and/or Vertical Move settings. While trying things out, make sure the Preview option is checked so you see what you're doing. Lastly, make sure only Transform Patterns is checked, so only the pattern is affected by your actions and nothing else.