Microcontroller soldering problem
If you are sure about chip then there are only 2 options left.
A) There is tiny hair that short these 2 pins. Looking the quality of your picture that I believe taken under microscope I cant see any hairs so this hypotheses is very unlikely. This is easy to check/fix. Just scratch between pins with lancet and test again.
B) More probable is that PCB etching was not done well. It may have defect or short under green paint that is not visible. If you try hard you may find the spot and try to fix it again with lancet. But this has to be hard cut at defected spot not just a scratch.
Other way to fix this without localising can be done with high current.
First remove your chip, then increase slowly voltage with current protected PS. At some point (hopefully short is not too big) shorting jumper should blow away.