Ok then, I am going to point you to check the for Nested Quotas with FSRM. This is from MSFT:
The "Used" and "Available" values for some of the quotas I have created do not correspond to the actual "Limit" setting.
Cause: You may have a nested quota, where the quota of a subfolder derives a more restrictive limit from the quota of its parent folder. For example, you might have a quota limit of 100 megabytes (MB) applied to a parent folder and a quota of 200 MB applied separately to each of its subfolders. If the parent folder has a total of 50 MB of data stored in it (the sum of the data stored in its subfolders), each of the subfolders will list only 50 MB of available space.
Under Quota Management, click Quotas. In the Results pane, select the quota entry that you are troubleshooting. In the Actions pane, click View Quotas Affecting Folder, and then look for quotas that are applied to the parent folders. This will allow you to identify which parent folder quotas have a lower storage limit setting than the quota you have selected.