LoadGenerator fails on third load test in a row with an OutOfMemoryError

[NSchmittUniWue]

The call resulting in the error is:
java -jar httploadgenerator.jar director --ip 10.1.3.37 --load static.csv -o log.csv --lua LU.lua --power "" --timeout 5000 --threads 256
The load intensity is constant for 180s at 1350 and the LUA script only calls a single REST endpoint.