Particle changes "transparency" based on angle of view, how do I fix?

Particle transparency changes

As seen as above, based on which angle I view the particle, the particles “transparency” changes (its actual transparency doesn’t change). This only happens when it’s positioned in front of another object. I don’t believe it has anything to do with its particle settings, as I have changed them a lot of times and it didn’t help. Changing the texture didn’t help either. Do any of you know how to fix it? Thanks!