I am using Eclipse Photon (also tested with Oxygene) with SonarLint for Eclipse Plugin (Version 3.6.0).
SonarQube Server has Version 7.2.1.14109, SonarJava Plugin is Version 5.6 (build 15032).
Problem
When opening some more Java files, Eclipse freezes for 20 seconds, with the message "fetching server issues for ". This behavoiur is not only on my machine, but also at some collegues machines. It appeares approx. 6 months ago, around this time we updated the sonarQube server to a newer Version 7.0 or 7.1.
I enabled the Eclipse “org.eclipse.ui.monitoring” Feature to log the according informations (and to prove it is the Sonar Lint plugin 
)
The generated files are attached.
UI freeze of 19s.txt (795 Bytes)
Sample1.txt (12.3 KB)
Hope you could help.
Wilko Grey