Multiple attachments in customer portal not added properly

Summary

Currently, when users add multiple attachments while creating an issue in customer portal. It will only take the latest attachment. For example, if there are Attachment 1 and Attachment 2, when the issue is created, it'll consist of 2 Attachments 2. It only affects when the attachments are added by screenshot (Copy and Paste). For example, Snipping Tool for Windows.

Steps to Replicate

1. Create an issue in customer portal.
2. Attach multiple attachments.
3. Create the issue
4. It'll only use the newest attached image.

Expected Result

It'll create the issue with the proper attachments.

Current Result

It is only taking the newest attached image.

UPDATE: This issue also happens when the images are posted in a different time or days after. If a customer pastes an image at the moment a ticket is opened and then paste another image on the next week and so on, but with the same name, it will show the thumbnail of the first image always. In some cases, it can also pick the last image and updated all other thumbnails. It can be confirmed by going to "Manage Attachments" where you can see the order of the attachments.