hAP ac^2 is fault (wifi problem)

Hello.

I have:

uptime: 5d21h17m47s
version: 6.45.5 (stable)
build-time: Aug/26/2019 10:56:37
factory-software: 6.43.10
free-memory: 73.7MiB
total-memory: 128.0MiB
cpu: ARMv7
cpu-count: 4
cpu-frequency: 716MHz
cpu-load: 0%
free-hdd-space: 2324.0KiB
total-hdd-space: 15.3MiB
write-sect-since-reboot: 9042
write-sect-total: 14574
bad-blocks: 0%
architecture-name: arm
board-name: hAP ac^2
platform: MikroTik

NAME VERSION SCHEDULED

0 routeros-arm 6.45.5
1 system 6.45.5
2 X ipv6 6.45.5
3 wireless 6.45.5
4 hotspot 6.45.5
5 mpls 6.45.5
6 routing 6.45.5
7 ppp 6.45.5
8 dhcp 6.45.5
9 security 6.45.5
10 advanced-tools 6.45.5

I bought on the aliexpress PC with wifi module rt2800pci.
After connecting via wifi and trying to copy a large file to the PC device, the hAP ac ^ 2 starts to work badly, sometimes it even freezes.
(I copy videos by rsync command)

hwinfo from my PC (by hwinfo program) in the attache.

I recently started using your products so I don’t know how to identify this problem in more detail.
hwinfo.txt (363 KB)