Hey shottoke,
I understand you mentioned this is the same PlayStation and EA account, but do you have any others that may have been used in the past at all?
The EA account you're posting with has never accessed Apex Legends on any platform up until just now, and it looks like the PSN account was linked here at some point last year. You mentioned not having played in at least a year, so if that's the case, it's very likely it was previously linked to the EA account that actually has the progress you're looking for. From there it would just be a matter of getting it re-linked to any prior account to try restoring access to that progress.