There are two types of ports you can use. The problem is with the MIDI port you're using (and i'm assuming this might be the case w/ FL Studio also, though i'm not 100% sure). and it wasn't me just being off-beat either lol. pain in the ass and is very unmotivating.
It sounded a hot mess and I had to spend countless minutes just moving midi notes.
They were so off beat that when I quantized, it didn't even quantize properly. but when I went to take a look at the playback. The problem I had was that my audio was being recorded on time (there was negligible latency). and it took about 2 months to figure out the fix.