I solved this problem:
The missing hands caused by H2N marks some hands as duplicated hand, so it skiped these imports.
H2N detects all hands as duplicated which hands were dealt to hero at the same second.
For example Hero plays 2 table at the same time and he gets
18/01/2018 14:57:08 AA at Table 1 and he also gets
18/01/2018 14:57:08 22 at Table 2
H2N detect this as duplication (because these hands gets the same Hand ID) and import only 1 hand from this 2 sample.
This is not guessing, I tested it and I could reproduce this problem.
I also wrote to support, I hope now you guys can fix this problem.