My Internet Speed dropping

[90Ninety]

My home internet is dropping out , and slowing down . To be fair not sure if this is related to the PFsense box but , I am thinking maybe there is something I can look into or check on the PFsense box

I have a Virgin Media Business line ( Coax /Cable) with Static IP , with a Hitron Modem ( Router in 'modem mode')

I have one LAN with my IOT devices connected ( Google Home, Android TV , Laptops ECT)

I pay for a 350MB D, 20 MBps U. Line but , several times a day the speed drops to 20MB and the Ping rises to 2000ms . This may be the service provider issue rather than a PFsense .

However what methods can I employ to research this further ?

[90Ninety]

I have a generic J1900 Black box