Nullness checker inside if expression inside a lambda not working correctly

[theit]

Checker Framework 3.48.4
Java 21

I have the following snippet inside my code:

private @Nullable ProxyData proxyData;

static class ProxyData {
	private @Nullable String host;
	private int port;
	private @Nullable String username;
	private @Nullable String password;
}

this.proxyData is later processed inside a lambda expression in the following method:

private void doProxyConfiguration() {
	executeMenu(() -> {
		System.out.println("Actual proxy configuration:");
		if (null != this.proxyData) {
			System.out.println("- Host:     " + this.proxyData.host);
			System.out.println("- Port:     " + this.proxyData.port);
			System.out.println("- Username: " + this.proxyData.username);
			System.out.println("- Passwort: " + this.proxyData.password);
		} else {
			System.out.println("- no proxy configured!");
		}
	}, //
	...
}

Checkerframework now complains in my Maven build that access to this.proxyData.port/username/password in the if expression deference a possibly-null reference this.proxyData:

(...)
[INFO] Compiling 8 source files with javac [forked debug release 21 module-path] to target\classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] ...\MyClass.java:[326,44] Fehler: [dereference.of.nullable] dereference of possibly-null reference this.proxyData
[ERROR] ...\MyClass.java:[327,44] Fehler: [dereference.of.nullable] dereference of possibly-null reference this.proxyData
[ERROR] ...\MyClass.java:[328,44] Fehler: [dereference.of.nullable] dereference of possibly-null reference this.proxyData
[INFO] 3 errors
(...)

This shouldn't happen because a) there's an explicit check for !=null, and b) the erroneous lines happen after this.proxyData.host is accessed.