[Azathoth]

It's possible that:

1) Your magazine springs are really weak and cannot feed.
2) Your magazines just don't like that feed nozzle on your hopup unit.
3) The magazines are not 'properly' seated in your magwell.
4) Your magazine release is causing the issue.

Your problems shouldn't exist with the hopup unit the neo is the best made hopup unit on the market.

What brand magazines are you using? I've run almost everyone brand of mag under the sun in my neo hopup at games when i get tossed spare mags and it always seats properly but many times the mags can't feed due to old springs.