PNG File not being recognized as having 2400px on Photoshop

So my Photoshop trial was over and I renewed it. I'm on this site online which does Print-on-demand
and the PNG files from photoshop have worked perfectly before the trial of Photoshop was over. But
as soon as the trial was over, the photoshop PNG files kept being acknowledged as being too small
and not 2400px wide when in fact I adjusted them correctly. I used a file from Paint and it worked fine
with the Print-on-demand site, but the file from Photoshop is not being accepted. What do I do?