How do you stream media between a seperated NUC and NAS without insane lag?

As title ask. I used to run lots of Docker containers on my Synology DS1522+, and it went extremely fast when streaming movies over my LAN-network, there was no smb overhead or anything that made it slow down.

But I want my NAS off the internet and use a seperated NUC as the docker handler instead. I ordered a 22 core i7 NUC with 64gb ram and good transcoder for movies, but mounting my NAS to it significantly slowed down movie watching, it is unbearably laggy.. It plays for one second and freezes for five.

I'm not a Linux expert, but I added the samba share to my NUC via sudo mount -a, after making a mount folder and appended the fstab file. I tried adding some "rsize" and "wsize" but that didn't help.

Any ideas on how to do this the best way would be greatly appreciated! Thanks in advance