@Jeeves. I've been thinking about this for the last couple of hours. A couple of things that might be of interest to whoever is trying to figure it out.
1. Quite often what is happening is this: Blue get free button is lit up but once clicked is fades in colour and the six dots continually "scroll". It's as if an ad that was there a second ago, now cannot be found. Sometimes an ad will be shown (but it feels like an eternity, maybe 10/15/20 seconds before it plays.) More often than not I get bored of waiting and exit the rests screen. Now what happens is a square appears in the centre of the screen, rotating through 90 degrees at a time, as if I have an Internet connection failure. The background screen of the game is also at this time "faded". To stop this it is necessary to enter another option of the game, fixtures, squad, home, whatever, it doesn't matter where. Then going back to the club shop everything is back to normal, could even be that the blue button (for any resource) is lit. This cycle can repeat or the no videos avaliable notice appear or even, a video is shown.
But, thinking about this cycle again, without moaning about it, it "feels" as if there is a connection failure. Is it possible that my account has a problem connecting to the ad providers?
Another thing that has me wondering are the ads that I'm getting. They seem to be restricted to the same 3 or 4 ads. Facebook, fleet commander, amazon(?), not sure about others. I will pay attention next time I get some. Could it be that I'm only getting ads from 1 provider? Is there a connection error to other providers?
2. Not sure if this will have any bearing on things. I have 2 teams. Team A is my original team linked to Facebook. Team B is a google play account NOT linked to Facebook. I have the same problems to get adverts with both teams, but it wasn't always like this. 7/8 months ago I had no problem getting 25/30 ads in one session for each team. Now, what may be of interest to whoever is looking into this is that both teams have the same email address. Hence team B is not, never has been and never will be connected to Facebook. Could this be causing a problem?
Again, it "feels" as if there is a connection loss to the ad provider.
Hope this might point the bug hunters in the right direction.