UserProfileIT.changeDefaultEditor is flickering

org.openqa.selenium.TimeoutException: 
Expected condition failed: waiting for org.xwiki.test.ui.XWikiWebDriver$1@1f967368 (tried for 10 second(s) with 500 milliseconds interval)
Build info: version: '3.141.59', revision: 'e82be7d358', time: '2018-11-14T08:17:03'
System info: host: 'aeb55526ebf3', ip: '172.17.0.2', os.name: 'Linux', os.arch: 'amd64', os.version: '4.9.185-xxxx-std-ipv6-64', java.version: '1.8.0_242'
Driver info: org.xwiki.test.ui.XWikiWebDriver
Capabilities {acceptInsecureCerts: true, browserName: firefox, browserVersion: 76.0.1, javascriptEnabled: true, moz:accessibilityChecks: false, moz:buildID: 20200507114007, moz:geckodriverVersion: 0.26.0, moz:headless: false, moz:processID: 79, moz:profile: /tmp/rust_mozprofile4IIENU, moz:shutdownTimeout: 60000, moz:useNonSpecCompliantPointerOrigin: false, moz:webdriverClick: true, pageLoadStrategy: normal, platform: LINUX, platformName: LINUX, platformVersion: 4.9.185-xxxx-std-ipv6-64, rotatable: false, setWindowRect: true, strictFileInteractability: false, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}, unhandledPromptBehavior: ignore, webdriver.remote.sessionid: 82f9db91-9516-43aa-a735-abd...}
Session ID: 82f9db91-9516-43aa-a735-abdd0116d8d5
	at org.openqa.selenium.support.ui.WebDriverWait.timeoutException(WebDriverWait.java:95)
	at org.openqa.selenium.support.ui.FluentWait.until(FluentWait.java:272)
	at sun.reflect.GeneratedMethodAccessor41.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.xwiki.test.ui.XWikiWebDriver.waitUntilCondition(XWikiWebDriver.java:238)
	at org.xwiki.test.ui.XWikiWebDriver.waitUntilElementsAreVisible(XWikiWebDriver.java:359)
	at org.xwiki.test.ui.XWikiWebDriver.waitUntilElementIsVisible(XWikiWebDriver.java:314)
	at org.xwiki.test.ui.XWikiWebDriver.waitUntilElementIsVisible(XWikiWebDriver.java:302)
	at org.xwiki.user.test.po.PreferencesUserProfilePage.<init>(PreferencesUserProfilePage.java:51)
	at org.xwiki.user.test.po.AbstractUserProfilePage.switchToPreferences(AbstractUserProfilePage.java:61)
	at org.xwiki.user.test.ui.UserProfileIT.changeDefaultEditor(UserProfileIT.java:213)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)