Antenna & Cable for HUAWEI b525s: Outdoor Wall/Chimney Mount, 15-20m Length, Signal Boost, Warsaw

Hello, I'm looking for an antenna for the Huawei b525s modem. We got it from Play and we have the same internet. We live in a house in Warsaw, but new blocks are being built around us that block our signal. Currently, there are 2-3 range lines out of 5 on the modem. The modem is on the window on the ground floor. What antenna would be appropriate and is there any length of cable from the antenna to the modem that should not be exceeded? Of course, I am thinking of an outdoor antenna mounted on a wall or chimney. What would be the approximate price of a 15-20 m antenna and cable?
As far as I know, the antennas of all operators are quite close, but unfortunately the range is not great. Possibly other ideas to improve the reception?

How is the location in Warsaw? Check if your B525 works with http://www.mediafire.com/file/1yz26m6u8gfl16n/E5186+Toolbox_latest+v0.9.zip or phone app http://www.mediafire.com/file/6164xqf8az6ju81/Huawei_Manager_PL.apk These programs show BTS LTE and CID (ECI) signal parameters. They allow you to force specific LTE bands and LTE-A aggregations on the router. You force LTE2600, LTE2100, LTE1800 and LTE800 in turn, and LTE2600 + 1800, LTE2600 + 800 and LTE1800 + 800 aggregations. You check the signal parameters, CID and speed. The choice of antenna depends on it and set it to the direction of a specific BTS. The cable is as short as possible, no more than 10m. each meter is a signal loss, the largest on LTE2600 which in Play has a 20MHz band in MIMO2x2 and is by definition the fastest.

Hi, I know it's been a while and the topic is dead. My fault doesn't change that.
I downloaded the application on the phone, made various settings, but unfortunately I can not draw conclusions. I am posting screenshots of what I got and if someone could see it, I would be very grateful. If anything else to post, let me know because I'm green on the topic.