Expected to read a START_MAP but instead have: END

[amywre...@gmail.com]

I have recently moved to selenium 4 from a much older version. My tests use the standalone driver and firefox - I am hitting a very intermittent error in our continuous tests and I am not sure what to look for in terms of the cause.  Maybe I should be setting something in capabiities that I'm not?  You can see what I have set below. The stack always looks like this from the point that we call FluentWait.until - usually like this : 

Wait<WebDriver> wait = new FluentWait<WebDriver>(driver).withTimeout(Duration.ofSeconds(10)).pollingEvery(Duration.ofMillis(250));

Thanks in Advance - 

Here is the failing stack - 

org.openqa.selenium.WebDriverException: 2021-12-10-22:46:23:653 Expected to read a START_MAP but instead have: END. Last 0 characters read:
Build info: version: '4.0.0', revision: '3a21814679'
System info: host: 'cdadd9268e9e', ip: '172.17.0.3', os.name: 'Linux', os.arch: 'amd64', os.version: '5.4.0-48-generic', java.version: '11.0.11'
Driver info: driver.version: unknown
Build info: version: '4.0.0', revision: '3a21814679'
System info: host: 'ne-b56cd-1435-4c0a-b777-c51e50d1587b-ebc-nanolnyfzvsg', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'amd64', os.version: '4.15.0-20-generic', java.version: '11.0.12'
Driver info: org.openqa.selenium.remote.RemoteWebDriver
Command: [f2177cb8-ae22-4144-884f-30ff2d13b41b, findElement {using=id, value=clusterA-actionButton-actionMenu-startButton}]
Capabilities {acceptInsecureCerts: true, browserName: firefox, browserVersion: 94.0, javascriptEnabled: true, moz:accessibilityChecks: false, moz:buildID: 20211028161635, moz:debuggerAddress: localhost:37582, moz:geckodriverVersion: 0.30.0, moz:headless: false, moz:processID: 169, moz:profile: /tmp/rust_mozprofile4hos3n, moz:shutdownTimeout: 60000, moz:useNonSpecCompliantPointerOrigin: false, moz:webdriverClick: true, pageLoadStrategy: normal, platform: LINUX, platformName: LINUX, platformVersion: 5.4.0-48-generic, proxy: Proxy(), se:cdp: ws://172.17.0.3:4444/sessio..., se:cdpVersion: 85, se:vnc: ws://172.17.0.3:4444/sessio..., se:vncEnabled: true, se:vncLocalAddress: ws://172.17.0.3:7900, setWindowRect: true, strictFileInteractability: false, timeouts: {implicit: 0, pageLoad: 300000, script: 30000}, unhandledPromptBehavior: dismiss and notify}
Session ID: f2177cb8-ae22-4144-884f-30ff2d13b41b
Build info: version: '4.0.0', revision: '3a21814679'
System info: host: 'ne-b56cd-1435-4c0a-b777-c51e50d1587b-ebc-nanolnyfzvsg', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'amd64', os.version: '4.15.0-20-generic', java.version: '11.0.12'
Driver info: driver.version: RemoteWebDriver
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.createException(W3CHttpResponseCodec.java:200)
at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:133)
at org.openqa.selenium.remote.codec.w3c.W3CHttpResponseCodec.decode(W3CHttpResponseCodec.java:53)
at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:184)
at org.openqa.selenium.remote.TracedCommandExecutor.execute(TracedCommandExecutor.java:39)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:559)
at org.openqa.selenium.remote.ElementLocation$ElementFinder$2.findElement(ElementLocation.java:162)
at org.openqa.selenium.remote.ElementLocation.findElement(ElementLocation.java:60)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:383)
at org.openqa.selenium.remote.RemoteWebDriver.findElement(RemoteWebDriver.java:375)
at org.openqa.selenium.support.ui.ExpectedConditions$7.apply(ExpectedConditions.java:197)
at org.openqa.selenium.support.ui.ExpectedConditions$7.apply(ExpectedConditions.java:193)
at org.openqa.selenium.support.ui.FluentWait.until(FluentWait.java:208)