Premature, delayed, painful, retrograde or absent. Different problems with different answers.
Premature ejaculation
The most common male sexual complaint. It is defined by consistently ejaculating sooner than wanted, with distress attached, and it comes in a lifelong form and an acquired form.
Acquired premature ejaculation often develops alongside erectile difficulty, where a man rushes before losing the erection. Treating the erectile problem frequently improves the ejaculation as a byproduct.
Either way it is frustrating for both partners, and it responds well to treatment.
Delayed or absent ejaculation
Medications are the most common cause, particularly SSRIs. Diabetes and the nerve changes that come with it are the next. Both can be addressed.
This gets under-reported because men assume nothing can be done about it.
Retrograde ejaculation
Semen travels backward into the bladder rather than out, producing little or no visible ejaculate and cloudy urine afterwards. It follows some prostate procedures, and it is also caused by certain medications, particularly alpha blockers used for an enlarged prostate.
It is not harmful, but it matters for fertility, and sometimes changing a medication resolves it.
Painful ejaculation
Worth evaluating rather than tolerating. Prostatitis and pelvic floor dysfunction are the usual contributors.
Reduced volume
Some decline is normal with age. A sudden change is worth investigating, and low testosterone is one cause. After a vasectomy the change is minimal, because the sperm fraction is less than five percent of the ejaculate.