Sq Ax - My Disappointment with Wifi 6

Hello team, I bought SXTsq-5axD device instead of my Ptp RBSXTsq5nD devices to be faster.

I did the configuration, the first disappointment was that even in superchannel there were 28 channels, I tried all of these channels, 20,40,80, 80+80, 160 mhz..

And even though these channels are not restricted in the country, there are restrictions on mikrotik side.

The first important problem is that the signal which is -40 in RBSXTsq5nD 350 meters is -55 -60 in RBSXTsq5nD.

In addition, it is not even close to the promised performance.

Mikrotik Wifi-6 was already very late, but it would have been better even if it never entered. Can such a thing happen?

The output of both devices is 16dbi, there is -20 signal loss no matter how you look at it.

Can you give me a logical explanation for this.