Available money is not Invested in custom Portfolio

Hello Community, I have created a custom portfolio with target 1000 € and paid that much into my account. Hold back is set to zero. When I defined the filters for the Portfolio, there were 400 notes meeting my requirements. With a minimum invest of 50€ , I expected the 1000 € to be invested in almost no time (it is just 20 invests, of 400 that qualified). Instead, investments are stuck at about 360 € for almost a week. The rest of the money sitting in my account as cash. There is a Mintos Portfolio of higher prio in my account, but this one has reached target (and if not, the money would go there, not remain uninvested. Any ideas anyone ? Or was I just misreading the 'available notes' when setting my filters?