4 month after fue and not all transplanted hairs has started to grow. Does it mean they will never grow?

It can take 6 to 12 months after surgery to see results.  If you are concerned it is best to contact your doctor.  4 month may be too early to judge.

EB1977,AT 4th month some of the grafts are beginning to grow out, but not all of them would do so at this time. It would take about 10 months for almost all the grafts to break skin. At 5-7 months sufficient number of grafts have broken skin enough to impart a cosmetically significant difference. So it would seem you are well within what is expected for the timeline.

4 months it is pretty common to not see any progress of growth. For some people, they may not see any growth until 8 months past the surgery, so at this point you don't need to be concerned, just be patient. If nothing is happening after 8 months then you should start worrying.