Sync Error from MacBook to Web: Missing 72 Attachments on Web

When I click on the sync status report on my MacBookPro (running OS 10.11.4) endnote (version 7.5.3) it says that everything is OK (no sync errors). Here below is the full report. Note the gap between the number of Local Sync Library Attachments of 2199 and the Online Sync Library Attachments of 2127 (4.97 GB). My main goal is to make these two numbers of attachments (local and online) to be identical. Maybe after this happens then all of my attachments will end up also on the iPadPro endnote (endnote version 2.2). As of now my iPadPro only has the 2127 attachments (same as the number that are online), and thus is missing the other 72 attachments that are on my MacBook endnote. Please help me to do this.

Sync Details

Sync was last run: Tuesday, May 03, 2016 at 20:51:17 PM -0500

Sync Status: All changes have been sent.

Error Code: None

Error Message: None

Local Sync Library

Library Name: Keas Universal Bibliography.enl

References: 2618

Groups: 126

Group Sets: 4

Attachments: 2199

Online Sync Library

References: 2618

Groups: 126

Group Sets: 4

Attachments: 2127 (4.97 GB)

Sync Limits

Number of References: 1000000 (997382 can still be added)

Number of Groups: 5000 (4874 can still be added)

Number of Group Sets: 5000 (4996 can still be added)

Attachment Storage: Unlimited