Specefic event is not sent to Amplitude

Hi, 
I’m new with Ampliture (and integration with it). I’m using Java SDK to send evemts to Amplitude.

amplitude.setLogMode(AmplitudeLog.LogMode.DEBUG)
amplitude.setEventUploadThreshold(100)
…
// define event and send
amplitude.logEvent(event)

It should be noted that I use Kotlin with courotines. 

I’m trying to import to Amplitude my latest events (e.g. for last 3 days). I can see allmaust all events in Amplitude but `first_result`. Neither in Data → Events tab, nor in User Look-Up page.
Debug mode shows that everything was sent correctly.
 

​​​​​​​SEND: Events count 100
RESPONSE: {
    "code": 200,
    "successBody": {
        "serverUploadTime": 1690390833497,
        "payloadSizeBytes": 74160,
        "eventsIngested": 100
    },
    "status": "SUCCESS"
}

I’m sure that I set API key correctly.
Also, when I try to create custom event with this name I receive error “Unable to create an event with a name that already exists”
​​​​​​​
I’m out of options now and will be glad for help