Created attachment 38270 [details] Simple testplan GUI interactions in JMeter 5.5 seem very slow and unresponsive compared to JMeter 5.4. Especially switching to the response view of the "View Results Tree" listener takes very long. I've attached a very simple testplan wth the following structure that shows this behavior for me: Testplan -View Results Tree -Thread Group -Debug Sampler
Have you tried a current nightly?
Seems to be a problem with the used java version: OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.5+10). After upgrading to a newer version of Java 11 everything works fine and GUI is responsive again: OpenJDK Runtime Environment Temurin-11.0.15+10 (build 11.0.15+10).
This issue has been migrated to GitHub: https://github.com/apache/jmeter/issues/5663