• I have tested the latest master version from http://builds.jabref.org/master/ and the problem persists

On:

JabRef 4.1 Windows 8.1 6.3 x86 Java 1.8.0_151
JabRef 4.2-dev Windows 8.1 6.3 x86 Java 1.8.0_151

Steps to reproduce:

1. Open entry editor
2. Right click on a field (e.g., title)
3. Select a text to protect its case, e.g., IEEE.
4. Right click --> protect items --> Add {} around selected text
5. Sometimes, {} appear for a moment around the selected text before quickly disappear.