Marius Dumitru Florea it seems it's still flickering, see for example: https://ci.xwiki.org/job/XWiki/job/xwiki-platform/job/stable-15.5.x/174/testReport/junit/org.xwiki.realtime.wysiwyg.test.ui/AllIT$NestedRealtimeWYSIWYGEditorIT/Platform_Builds___main___integration_tests___IT_for_xwiki_platform_core_xwiki_platform_realtime_xwiki_platform_realtime_wysiwyg_xwiki_platform_realtime_wysiwyg_test_xwiki_platform_realtime_wysiwyg_test_docker___Build_for_IT_for_xwiki_platform_core_xwiki_platform_realtime_xwiki_platform_realtime_wysiwyg_xwiki_platform_realtime_wysiwyg_test_xwiki_platform_realtime_wysiwyg_test_docker___imageWithCaption_TestReference__TestUtils_/