Slow speed, intermittent dropouts, breaks in the signal or no signal on some or all devices or no internet access might be caused by Wi-Fi interference from other local networks, which can also lead to a permanent reduction in speed. No ISP can be responsible for your local environment, this is mainly a byproduct of the popularity of Wi-Fi. Where the laptop is in your property compared to your iPhone.
In addition to that, it may depend on which WiFi band your laptop is connected to, plus it could be down to the WiFi adapter in your laptop.
If it is a Windows laptop, please can you go into the command prompt & PM me the output from two commands:-
netsh wlan show interface
netsh wlan show drivers
