Keep getting no signal on random channels, even in good weather.

[Greenblack]

• Hi, I can only get signal on a few channels at a time. The channels affected tend to be random. Sometimes Sky & ITV. Sometimes only BBC. This is regardless of the weather & has been happening for almost 6 months and is getting worse. I use communal dish in a flat building. I dont have a landlord as it's a part ownership. Thank you in advance for your help.

[Mark39]

It's  most likely to because of a fault with the communal system. You'd need to report it to whoever owns tje communal system.