Login page username issue

Hello Experts,

We have a weird issue.

When we open Oracle on a fresh browser, it auto populates a different username on a machine who never accessed Oracle on that machine.

For example, on a laptop belongs to user 'A', the username 'X' auto populates and X never logged onto Oracle using A's laptop.

This happens randomly and couldn't find any specific reason.

Any pointers on this will be highly appreciated.

Thanks,

Satheesh