been there, done that. suspension or water based TNE are annoying as f uck if the powder isnt micronized.
ur problem is probably happening because ur pinning down (ie quad, glute) and the powder is clogging the needle.
try pinning ur delt. if doing left shoulder, lean to the left and insert the needle at an upward angle.
u can also try adding some Bac Water to the syringe....that helped tons