I have somewhat the same problem, with fundraising at 25%. And after checking the wikia, which says: "The points actually got for a contract decrease exponentially as the level gets nearer to the limit so a player will never reach it", I think I understand what's happening. Imagine you have your rep at 500. You do a mission which should give you 500. You would think that you would end up with 1000 rep. But, since the value is already high, you only recieve a small % of that value, (let's say 10%), and you end up with 550 rep. Everything normal here. Now, with fundraising at 50%, you would recieve 250 (50% of 500), and have 750. But, again, with the exponencial value, you should recieve less, just about 25 (50% of 10% of 500), and end up with 525. Now the problem with the game. Instead of you gaining only 10%, and losing half of it (50-25), You are gaining 10% (50), but losing half of the original value (which was 500, meaning you're losing 250). The end result after doing this mission, is 300 (you started with 500, meaning you lost rep doing a mission). These are my two cent