Unable to Use Two Accounts for Splitscreen on PS4

Hello.

I'm experiencing an issue when trying to log into two different accounts on the same PlayStation 4 console for splitscreen play.

As shown in the image below, the second account appears with the same ID as the first one, but with a “(1)” added to it. Additionally, when viewing who is online, three accounts show up with the same ID, which is very confusing.

Could you please assist in resolving this issue or explain why this might be happening?

Thank you in advance for your support.