OK, so I don't have enough knowledge to pinpoint the reasons for this problem, but as I said earlier, the problem was propably caused by terraforming and building activity in the region. As you can see from the dump in the previous post, yhe allocated memory was 934.8 MB. I asked for a restart of the region, and after restart the memory allocated was down to 90,7MB and eveything is working as it should.
PROBLEM SOLVED!!