Unknown user despite userId, userName set.

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

Unclear.
Event which exhibits the problem: [us.sentry.io.json](https://github.com/getsentry/sentry/files/15194832/us.sentry.io.json)
Event which shows the user correctly: [us.sentry.io.json](https://github.com/getsentry/sentry/files/15194865/us.sentry.io.json)
You will notice, both events contain an e-mail address and user name in the user key.
We do notice that the problem exhibits on iOS whereas the working issue was reported under Linux.
Both events are for the same project.

open func startCrashLogger() {
SentrySDK.start(configureOptions: self.sentry(options:))
}

open func sentry(options: Sentry.Options) {
// TODO: https://github.com/getsentry/team-mobile/issues/24
// options.enabled = false
options.sendDefaultPii = true
options.environment = AppInfo.shared.configuration.lowercased()
options.enablePreWarmedAppStartTracing = true
options.enableMetricKit = true
options.swiftAsyncStacktraces = true
options.initialScope = self.sentry(scope:)
options.beforeSend = self.sentry(event:)
options.attachScreenshot = true
options.attachViewHierarchy = true
options.dsn = "https://68d13d7dab6f450090a1045d141b108f@o378389.ingest.sentry.io/5225762"
options.tracesSampleRate = 0.1
options.profilesSampleRate = 0.1
}

open func sentry(scope: Sentry.Scope) -> Sentry.Scope {
scope.setTag(value: AppInfo.shared.build, key: "app.build")
scope.setTag(value: AppInfo.shared.version, key: "app.version")
scope.setTag(value: AppInfo.shared.configuration, key: "app.configuration")
scope.setTag(value: AppInfo.shared.reference, key: "app.reference")
scope.setTag(value: AppInfo.shared.revision, key: "app.revision")
return scope
}

open func sentry(event: Sentry.Event) -> Sentry.Event? {
event
}

### Expected Result

I expect both events to show the user described under the Tags header in the Sentry report.

### Actual Result

(Note however that both events correctly report the user in the details area)

Event which exhibits the problem:

Event which shows the user correctly:

### Product Area

Issues

### Link

https://hubstaff.sentry.io/issues/5278254369/events/863b8b8487bb46e08927cb2dfbc97d5b/

### DSN

https://68d13d7dab6f450090a1045d141b108f@o378389.ingest.sentry.io/5225762

### Version

_No response_