A guy on Facebook grp gave this as an possible explanation.
And it kinda make sense and easy to overlook as Dev i dont know.
"I have had similar problems in my saves and tried to "check under the hood" for answers and I think that I have found the answer:
As you probably know, the quality in facilites is rated from 1-20 in the match engine, where 20 equals "state of the art". However, most of the time when you upgrade your facilities, they are upgraded by 2 points each time. So from 10 to 12, 11 to 13 etc.
The problem here, I think, is that facilities won't be upgraded if there isn't room to develope these 2 points. In your case, you have "superb facilities" meaning that they are either at 18 points or 19 points. My theory is that if your facilities were at 18 points, you would be able to upgrade to 20. But alas, you probably have 19 points, meaning that there isn't room enough for the 2-point upgrade, resulting in the board not seeing the point of spending money on upgrades (or some other narrative explanation).
So if you were to download some sort of FM scouting tool (or editor), and look at your club facilities, my guess is that they are 19 for training facilities and 20 for anything "state of the art".
The problem is that I think most of the time, facilities are downgraded by 2 points at a time as well, meaning that a club that has an odd numbered points in facilities won't ever be allowed to reach state of the art. But I haven't tried this out so I can well be wrong about that. If they downgrade 1 point at a time, then you can just wait for that to happen and try upgrading them from 18 to 20."