You can try to ask the support, but I guess that this change was made because we had a issue, that did not count the % possession bonus from the max. attendance allowed per level, it counted the 100% as the capacity of your stadium and then, for example if you had a limit per level of 19k.... it did not calculate the 100% from that level limit of 19K, so, it was wrong and those like you who had 19k fans attending with a bigger stadium saw the % attendance bonus reduced due this issue.
So basically you have the upgrade, but it will not say 19/31k probably because this creates an error in the calculations.
But thats my theory with my supposition and knowledge of what occured, so I invite you to write a ticket in the support and ask for more info.![]()