Is anyone have experiencing quantity issues

[Armstrong1]

We just spent an enormous amount of time doing inventory, updating it in the system, and such.

Yesterday - we noticed one of the counts is over 400 less than we had 2 weeks ago - we knew we did not sell 400 items but recounted and the difference was nearly 400.

Reviewing other items it was noticed that there are negative numbers for products that we just updated. For example we had zero of eraser item, we received in 12.  We have sold 3 which was confirmed as there are still 9 erasers remaining, but the inventory is showing a negative 6.

This happened last year as well and Square stated it had something to do with an update. 

Is anyone else having this issue? If so, how did you fix it?