@Jossiboy - There reason for that is because there's two different ways GS is calculated:
The GS showing on your character takes into account your 3 weapons and your 6 year pieces. For example, if you have all 229 weapons and 268 gear pieces, your GS would be 255 on your screen: (3x229 + 6x268)/9 = (687 + 1608)/9 = 2295/9 = 255.
The GS for DZ purposes looks at your highest GS non-sidearm weapon (primary or secondary) and your 6 gear pieces. Using the same example above, your DZ GS would be 262: (229 + 6x268)/7 = (229 + 1608)/7 = 1837/7 = 262.4.
In both of the above examples, the game looks at equipped items, items in your inventory, and items in your stash when it figures the highest value GS item for each location. The different calculation for the DZ GS was created to counteract cheating players that would equip really low level secondary and sidearm weapons to artificially decrease their GS to get into lower level DZs to troll lower level players.
If you need help figuring what your DZ GS is (not that it really matters if it's over 231), post up the highest GS weapon you have, and the highest GS item for chest, knees, backpack, gloves, holster, and mask and I'll post up the math on here for you. Remember, check equipped items, items in inventory, and items in your stash for these numbers. From there you'd be able to see how changing around your gear (equipped, inventory, stash) will change what DZ you're in.