Neural plugin issues in UA luna

hello i am new here. i am a fractal user an recently purchased a Quad Cortex. i also recently purchased some of the neural plugins. i am having some issues understanding how to get a good sound with the plugins. in standalone they sound great but when i use the as an insert in UA luna i have to bring the buffer down to 128 to get a decent sound any higher buffer setting they do not sound good and i have latency issues. i also tried to use them in a track in logic and the outcome was even worse. Am i doing something wrong? thanks in advance