Help to solve strange Down/Up wireless speed behavior

Hello, I am new at mikrotik forum, but not new with mikrotik equipment. My problem is not a “disaster problem” but I cannot figure out why it’s happening. My setup are two MikroTik LHG XL 5 ac antennas with point to point bridge setup of disantace ~1.5 - 2 km. Although the path is not completely clear.

Uplink: 1000 Mbps optical fiber > Netis 1Gbps router > Point to Point Bridge (LHG XL 5 ac) > Mikrotik with RouterOS (100 Mbps) > MikrotikSwitch > End Point stuFF

IPv4 + IPv6 network setup at the end of: Mikrotik with RouterOS (100 Mbps) - Hurricane Electric tunnel broker setup to maintain IPv6 over IPv4

Everything works fine I’ve got Netis IPv4 external IP and IPv6 from Mikrotik Router.
:~$ ping google.com
PING google.com (172.217.16.14) 56(84) bytes of data.
64 bytes from waw02s13-in-f14.1e100.net (172.217.16.14): icmp_seq=1 ttl=46 time=53.8 ms
64 bytes from waw02s13-in-f14.1e100.net (172.217.16.14): icmp_seq=2 ttl=46 time=50.6 ms
64 bytes from waw02s13-in-f14.1e100.net (172.217.16.14): icmp_seq=3 ttl=46 time=48.7 ms

~$ ping6 google.com
PING google.com(waw02s13-in-x0e.1e100.net (2a00:1450:401b:804::200e)) 56 data bytes
64 bytes from waw02s13-in-x0e.1e100.net (2a00:1450:401b:804::200e): icmp_seq=1 ttl=57 time=37.7 ms
64 bytes from waw02s13-in-x0e.1e100.net (2a00:1450:401b:804::200e): icmp_seq=2 ttl=57 time=28.8 ms
64 bytes from waw02s13-in-x0e.1e100.net (2a00:1450:401b:804::200e): icmp_seq=3 ttl=57 time=25.9 ms

Strange behaviour is my speed. I am getting only ~1-8 Mbps on web browsing, file downloading from one point servers.

Another example:

SpeedTest.net:
Downloading ~10 Mbps and dropping to average of 5-6 Mbps
Uploading ~12Mbps and dropping to average of 10 Mbps

Torrent:
Downloading ~50-80 Mbps
Uploading ~60-85 Mbps

Another example:
To download from github a binary package is painful. Downloading only 128-256Kbps which is really strange behaviour for me.

Any ideas what to look for?
Thanks!