"Would the solvent in the 2k primer seep down through the paint and impact the existing primer? I'm not that familiar with the chemistry of these paints/ primers."

Yes, it can seep through and cause lifting. Best remedy is to sand the whole area to bare metal , then spray with the 2K primer.
Look at the way the whole panel is lifting. Either the primer that the PO put on was inferior or there was poor prep done before topcoating. Could be both. Sand that whole panel down to metal, prime with 2K.