Its both. Pre cat is not the greatest to sand at the best of times but pigmented versions are a bit worse. Higher gloss is worse than lower gloss as well.

You should expect to get a good finish straight off the gun. Pre cats work best if done over 2 days. First coat day 1, leave over night, sand, 2nd coat, dry for a while then de-nib and apply final coat. Repeat the last 2 steps if you want a fuller finish. Cheers