Does Semen Blockage Cause Small, Painful Lump In Testicle With Painful Ejaculation?

Hi, my question is regarding my fiance. we are strictly monogymous and he has recently formed a small lump in his left testicle. It is painful. He did 10 flights of stairs today and it started hurting after that. He has had this before and the urologist said it was a semen blockage. This time it came on after doing those flights of stairs but he says he has the very same symptoms that he had last time. Symptoms include, a small lump on the side of his teste, pain with no relief, made worse by touch, movement, ejaculation is extremely painful afterwards. Could this be caused by something other than a seminal blockage or bacterial infection aside from STD? The last time he had this they gave him antibiotics and it cleared it up even though he had dealt with the pain for 8 months prior. His main question is it solely STD infections that cause these siince there was no injury either time, and he had a clean STD test. Thank you in advance!