Just to make sure I'm understanding correctly, it sounds like this was your situation.
EA account 1: PSN account + progress
EA account 2: Steam account + progress
Then you had mentioned moving your Steam account to the EA account that had all your prior progress, but you're now seeing your Steam account is level 1. That would be due to this:
EA account 1: PSN account + progress, Steam account
EA account 2: Steam progress
Progress cannot be moved from one EA account to another, so when you unlinked the Steam account that progress remained behind. This would be why you're not seeing anything when logging in on Steam now.
With that said, once Cross Progression arrives on your EA account 1 (in this example), you'll be able to access that progress/content on both PSN and Steam, as well as any other platforms you may link to the same account in the future.
This is rolling out over time, so keep an eye out for the notification to appear in-game once this takes place for your account.