Slow connection on Smart Hub 2

[lendoo]

Hi, I have wifi issue since a month.
With wired connection I have no issues. 
Since a month the Hub restart itself frequency. Sometimes in every 10 mins, sometimes 2 -3 times a day...
After restarting the download speed drop down drastically.  5-6 Mbps or more... Sometimes less than 1Mbps. 

If I reset the HUB (switch off till 10 sec), the download speed increase to 30-35 Mbps but 5-10 mins later the HUB restrart itself and the download speed drop down again... This mean the wifi is totally unusable. 
Here is my Broadband Availability Checker: 

And here is my technical log info:

Product name:

BT Hub 6A

Serial number:

+084319+NQ72275343

Firmware version:

SG4B1000E079

Firmware updated:

20-May-2022

Board version:

1.0

Gui version:

1.126.0

DSL uptime:

0 Days, 0 Hours 9 Minutes 42 Seconds

Data rate:

15.31 Mbps / 24.92 Mbps

Maximum data rate:

15533 / 35217

Noise margin:

6.1 dB / 9.8 dB

Line attenuation:

50.4 dB

Signal attenuation:

36.2 dB / 50.4 dB

VPI / VCI:

0/38

Modulation:

G_993_2_ANNEX_B

Latency type:

Fast Path

Data sent / received:

109 MB Uploaded / 1 GB Downloaded

Broadband username:

bthomehub@btbroadband.com

BT Wi-fi:

Active

2.4 GHz wireless network name:

BTHub6-5P7R

2.4 GHz wireless channel:

Smart (Channel 11)

5 GHz wireless network name:

BTHub6-5P7R

5 GHz wireless channel:

Smart (Channel 36)

Wireless security:

WPA2 (Recommended)

Wireless mode:

Mode 1

Firewall:

On

MAC address:

84:A1:D1:B8:BD:5D

Software variant:

-

Boot loader:

7.33.1

Till long time (more than 5 years) I had not any wifi issues at all. 
Any suggestion?
Need I a new HUB?

[lendoo]

Today morning I also tested the speed on wired connection:
Here is the result:

[imjolly]

provided you don't have digital voice and you check your phone line for a dial tone  then dial 17070 option 2 it should be silent and best with corded phone   if no dial tone or your hear line noise then report phone fault to 150 if phone works or 03301234150 from mobile