Blue Iris

Dear Support / admin

I bought Blue Iris V5 software through a vendor from my office, because the
PC Server that I bought hasn't arrived yet, so I tried it with a trial
version on another PC Server,
with configuration:
- Supermicro 5018D-FN4T
- Intel (R) Xeon Silver 4110 CPU @ 2.10 GHz (2 processors), 32 cores
- 32GB RAM
- Graphic Card, NVidia Quadro P4000
- Windows 10 64-bit
- 2 x Capture cards, Blackmagic Decklink Duo 2, 4 inputs each, maximum plan
for 16 inputs
- Hard disk system, Intel SSD 1.6 TB
- Raid hard drive with Raid Card for Record Media

Configuration in Blue iris:
- Capture card in HD settings (1920x1080)
- Preview and record in HD settings

Problems I found:
- Live preview and stream position of each camera results are not smooth or
not like the original from the source, it looks lost frame
- When I change the audio video delay and get a preview that is almost
synchronized, but the results of the record do not sync, that also happens
when I change the audio video delay and get a sync record, but the preview
results do not sync

Please guide me, for the right configuration, to get the preview and record
sync between video and audio and the results smooth