Zebra DS3608 - inconsistent USB scan result when pasting into Java-based applications

Hello,

My company is writing application for customer, that allows him to scan his goods using Zebra DS3608 scanner. Barcode is a 3 multinumber fields separated by Group Separator signs. My software replaces GS signs with ';' in Swing KeyListener and extract this data later in the process.

I have discovered issues when using this scanner. It is connected to Win10 PC through USB as HID device. When i am scanning into my application sometimes there are some random ASCII characters instead of GS sign (○, ↔, ˘) which causes error in my process.

I was scanning into apps:
Notepad++
Notepad
MS Office Word 2010
Oracle SQL Developer
JavaPad https://www.javatpoint.com/notepad
My app

I had no problems with NotePad++, Notepad and Word - i scanned over 100x times with no issues. SQL Developer, JavaPad and my app had problems, all of them are Java-based so that is why I think it might be Java related.

My environment:
Java: JDK 1.8.0_65 (company requirement)
System: Win10

How can i make my scans 100% accurate?

Regards,
Mateusz