Slow speeds on newly designed network

[GTCG]

Greetings everyone!

So I've completely redesigned my home network and setup VLAN's with Ubiquiti material which consists of 1 Edgerouter X, 1 Ubiquiti 8 ports switch and two 5 ports flex mini switches. Before I redesigned my network I was able to get transfer speeds to my NAS with a speed of around 100MB/sec. Now I seem to have fallen back to 20MB/sec. Protocol is SMB.
As it is, I am transferring files from my Management VLAN to the IOT VLAN, where the NAS lives. It is a Gigabit network, I checked all cables, they are all CAT6.
When files get transferred they go from my management PC (192.168.110.6) to the router interface of the Management VLAN (192.168.110.1) and from there to my NAS on 192.168.140.3
Could it be the bottleneck is the firewall of the router? I've configured the firewall in that way that the Management VLAN has full access to the IOT VLAN.
Putting the NAS in the management VLAN or disabling the firewall are not viable options. Can I do something else to get to faster transfer speeds?

Specs of my NAS are as follows:
- Build: 11.1-u7
- Platform: Intel(R) Celeron(R) CPU G1610T @ 2.30GHz
- RAM: 16GB

There are no VLAN's defined on the interfaces of the NAS itself. No tunables have been configured. The NAS get's its IP from my Routers DHCP server (which I configured as static via MAC binding.)

Don't really know where to look or how to tackle this issue.

 

[thewizard]

Possibly the Edgerouter X, see a few forum posts of people saying they max out around 200-300mbps which is about what you are seeing. Can you bypass it for LAN traffic?

 

[GTCG]

Well, can you believe it? I *thought* I enabled hardware offloading on the edgerouter X, but I was wrong. That was the reason for my issue.
Go to your edgerouter CLI en execute the following commands:
configure

set system offload hwnat enable
set system offload ipsec enable

commit ; save

This will not work when you are using QOS and VPN on the EX. So check your own situation if this an option for you.