Xpress ignores memory limits

I'm running a Mip model through Xpress 9.2.5, python interface. Halfway the solve, the solve process is killed due to an out-of-memory error: Out of memory: Killed process 5270 (python)

I tried imposing memory limits:

xp.controls.resourcestrategy = 1

xp.controls.maxmemorysoft = 9216

But I still get the same error. Please find attached a log of the solve process. At the top of the log file:

Minimizing MILP noname using up to 16 threads and up to 9216MB memory, with these control settings

Then at the end of the log file:

Heap usage of Sub-MIP solves: 23.7GB total, 0.8GB used by B&B trees

It seems the memory limit, as well as the available system memory, are completely ignored. Memory keeps just filling up until the process eventually dies. How can I fix this? This particular system has 32Gb of memory.