All of these things depend on so very many variables & not being there, it is especially difficult to responsibly give advice. The pics will really go a long way towards this end however...

With this said, several established growers routinely run veg nutes through week 2 of flowering, then switch to their bloom base nutes & perhaps start the p/k boosts here too, if used. The logic is that it addresses the N def shock of transition & establishes a strong stock of N throughout the remainder of the grow. This is IF the N issue is your root problem, this suggestion could work the next time around.

If you are nuting it at any normal level & are having N issues, then there is likely a pH lockout issue in your medium. What is your starting pH of the nute solution & at the run-off? Again, pics will really help in getting your answers. Best brah.