Alocasia Zebrina always loses leaves when new growth occurs?

The Alocasias I own always lose as many leaves as new ones grow. Currently (as can be seen from the picture), for example, the two oldest leaves are now turning yellow, and two new ones are growing. Firstly, it looks stupid, and secondly, it annoys me that it only has four leaves. One variety even has only one. What am I doing wrong, or what can I do better? Is repotting into a larger pot advisable? I'll repot soon and test a new soil mix (coconut soil, pine bark, perlite, each in a 1:3 ratio).