Is it normal for 5GHz WiFi speeds to drop at 100Mbps through a wall just one brick thick?

Question

Computer networks

I installed a new WiFi module of the QCNFA34AC type in the Lenovo Z70-80 laptop to be able to work in the 5GHz range. The module was purchased on Ali, I specifically chose one that is allowed in the white list in the BIOS of this laptop according to the Hardware maintenance manual for it. The new WiFi adapter worked, I installed the latest drivers from the Lenovo website on it.
Then he took up measuring the speed of information transfer through it, the following indicators were obtained:
1) The room in which the WiFi router (Zyxel Keenetic Ultra II) is installed is 570 ... 581 Mbps, with a signal level of -39 dBm.
2) Neighboring room, through a brick-thick wall - 398...421Mbps, at -48dBm, respectively.
The information transfer speeds are indicated specifically for the laptop, since they are more important to me, there was less return. Measurements were made by copying a large file from an old computer connected to the same router with a twisted pair cable at a speed of 1Gbps. The file was located on the SSD, and was also copied to the SSD in the laptop.
Is such a drop in speed normal, because the obstacle is not so significant, or for a frequency of 5 GHz, even such a wall is already a lot?
Also, the laptop was recently disassembled, and I accidentally damaged one coaxial cable near the antenna itself, it is there in the form of a sticker on the top of the laptop case. I damaged the one connected to the main connector on the WiFi module, and that is, another one connected to another antenna of the same design. I unsoldered the cable, cut off the damaged area and soldered it again, but it became shorter, and the screen itself shifted a little up when soldering - in a picture of a similar antenna from the Internet, I indicated exactly where and approximately how much, and added a picture how it turned out. I displaced it with solder, as if something was soldered to the solder pad on the board next to it, without stripping the insulating mask under it.
Could shortening the cable (after all, now both are of different lengths) and shifting the soldering point of the shield of one of them somehow negatively affect the level of the received signal? I did not measure the level of reception before him. I just don’t know if it’s worth looking for a new similar antenna, or if the reception level will not be better.

Answer 1

Is it normal for 5GHz WiFi speeds to drop at 100Mbps through a wall just one brick thick?

WiFi can only work stably in line-of-sight conditions. Without any bricks. If there is a wall made of brick, the signal should be very weak.
This is for the 2.4GHz band.
And the 5GHz range is good precisely because any obstacles dampen its signal much more effectively.
A one-brick wall should completely dampen the signal. Most likely reflected.

Answer 2

Yes, you're all right. The higher the gigahertz, the more opaque the walls! If there was a concrete wall, in general, God forbid I would get 50 megabits. 5GHz work only on line of sight!