DISC Lite5 ac poor bridge performance

The topic is about the DISC Lite5 ac.
I cannot exceed data transmission speed of ~200mbps trying to copy a file between PCs in windows using this hardware in scenario listed below.
Am I limited by hardware or configuring something wrong?

(PC1->LAN 1Gbps<- AP 4x4 MIMO->866,7Mbps 80MHz/2S/SGI<-Wlan1 RB DiscLite5AC LAN ->LAN 1Gbps<-PC2) ~190Mbps when wifi is connected in mode: station pseudobridge, and around ~150Mbps when in station mode, LAN and Wlan are bridged

I have restored the device configuration to the default - cleared it completely,
after that only the necessary changes were made to connect to the wifi network and create a bridge (by adding ether1 and wlan1 interfaces to it)
I have also assigned a network address (192.168.0.2/24) to the bridge
The hardware offload indicator is lit only by the ether1 LAN port.
The wifi SNR is ~45dB and overall Tx CCQ and Tx/Rx CCQ ~99%-100% Noise Floor -106dBm
CCQ fluctuate +/- 2% when transfering files.

When PC2 Connects directly to AP over a wifi card as explained below
(PC1->LAN 1Gbps<- AP 4x4 MIMO-> Wifi<-PC2) The transfer speed is ~950Mbit
Why is the RB DISC Lite5 ac a limiting factor - what am I doing wrong.

Is the hardware the limiting factor and should i consider an upgrade to RB922UAGS-5HPacT-NM and hope that the 3x3 when connected at max aggregate link rate of 1300Mbps will deliver those near gigabit transfer speeds?
Or should i consider other hardware as I am open to suggestions and set on that ~1Gig wifi transfer speed