WiFi Strength decreases - Laptop V5

Hi

I sometimes set my V5 laptop up to an external monitor and wireless keyboard/mouse to operate like I’m using a desktop. Recently, I noticed my wireless download/upload to be very slow (speeds 1mb) when it's connected to the monitor etc. so I contacted my internet provider and they changed the channel, carried out some tests and all was good (speeds up to 60mb).

Today, I discovered slow speeds and I have located the problem and it seems to be the laptop. I have the lid shut when it's connected to the external monitor because of space & protection and the power charge on and the signal strength drops. I even run the test with an open lid and I was getting 50mb+ closed the lid back down again (the laptop remain switched to the external monitor during this.

I have checked the power settings and the wireless is set at maximum on the setting.

Why does this happen and how can I remain to use the same set up (external monitor, wireless keyboard/mouse) with the lid shut but maximise my download speeds of 50mb+