hi im having problem with merging existing users who signed up in the past into present Amplitude.

I’ve tried getting data of existing users who were signed up before I used Amplitude.
I’ve tried with two ways(HTTP V2 API, Batch API) with event types like iAmplitude] New User, eAmplitude] Merged User and custom event types like ‘Batch_SignedUp’. It was successful so far cuz I could see the history events of the user.
But eventhough the user had history event like ‘Batch_SignedUp’ in the past, it shows up on the segmentation dashboard showing New User(event) . the usere shouldn’t be there cuz they were not new users when i check their user streams.
so im filtering them by using segment ‘users who performed Batch_SignedUp’.

is this general situation or am i doing sth wrong?

would be better old users(who signed up before i started using Amplitude) to get filtered correctly so that they won’t be considered as new user.(now, considered as new user at the time the did sth after i installed Amplitude)