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

JabRef 4.1 or
JabRef 4.2-dev--snapshot--2018-02-16--master--bb2b07833
Linux 3.13.0-141-generic amd64
Java 1.8.0_162

Steps to reproduce:

1. Connect to shared database on remote MySQL server with somewhat less-than-ideal connection speed/latency (SSH tunnel in this particular case).
2. Open an entry in the Entry Editor.
3. Typing is extremely slow, practically unusable.

Notes:

• No error messages on console/event log.
• Size of database is irrelevant (problem is the same even with new entry in empty database).
• Connection to database seems reasonably fast/responsive. No perceptible lag on the mysql command line.