Has anyone been having issues with the InfinityLab Poroshell 120 EC-C18 columns (PN 696975-302)? We ordered one, and tried our daily check solution on it but the results did not look like what we normally see. We also observed that the starting column pressure was lower (165 bar), and went really low (25 bar) as the gradient switched to more organic mobile phase. We asked for and received a replacement column, and that one worked as expected for about 3 weeks. Today we saw the same problem with the daily check. We checked for leaks, but did not find any. We have the same column on another instrument that has been functioning normally for months now. Has anyone else been having issues with these columns? Any ideas what could be causing this? Thanks in advance.