From what I get, it is related to Chartered Banks. A bank updated so the overall max increased by 500k. The display updates once per day but the mechanism works immediately it seems.
Not something we will attempt to deal with as chartered banks and the way they work, can result in such cases. For example, if tomorrow CDV leaves TK, then Pulpop's bank max limit will drop well below 144.5M. Then you will again have more gc in than the maximum allowed.
So, when this happens, it should not be regarded as a bug. Although, we will explore if we can update the display when the mechanism is indeed used.
At all cases, try to add 1M more now, to see if there is a permanent 500k extra room or if it is only related to update timing.