Problem after converting to LUKS2

Hi,

I have 3 partitions encrypted years ago with LUKS1.
I've decided to migrate them to LUKS2 and the first 2 there was no 
problem, but the last I can open it anymore after the conversion.

I've been using key-files for all of them, so there is no wrong password 
input issue.

The bad think is I don't have a header backup before the conversion (Yes 
I know! Lessen learned!)

I've tried different things like converting back to luks1 and header 
repair but to no avail.

As a last resort I'm writing here for help. Is there anything I can try 
to at least read the partition?

Thanks in advance.