Catch up on some Sky Programmes ie on Witness not available! why

[mazzzy62]

Due to signal issues  - which happens alot in the Summer - ie Communal dish being blocked by trees - most of the programmes on Sky + are frozen and unwatchable - therefore I catch them on the Catch-up.  However, in regards to Sky Witness, some are available others are not ie Chicago PD - why has this become an issue all of a sudden.  For the price I pay, I expect a better service.  

[SKY1992bf]

@mazzzy62  what is happening when you try watching them, unless they have been removed from on demand which happens has programs come and go and then return all the time for rights reasons 

if a series is currently broadcasting then each episode is only available on catch up for 30 days from original broadcast date 

[oj01]

I download all 3 Chicago's every week without issue.