`stack_compress` is not working with more than one value

When I try to use stack_compress with more than one value I get the following error (I use the latest version installed with pip and python 3.8)

Traceback (most recent call last):
  File "test_rb2.py", line 6, in <module>
    prb = PrioritizedReplayBuffer(buffer_size, stack_compress=["obs", "next_obs"],
  File "cpprb/PyReplayBuffer.pyx", line 986, in cpprb.PyReplayBuffer.ReplayBuffer.__cinit__
  File "cpprb/PyReplayBuffer.pyx", line 498, in cpprb.PyReplayBuffer.dict2buffer
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Below is a minimal example to try

import numpy as np
from cpprb import PrioritizedReplayBuffer

buffer_size = 256

prb = PrioritizedReplayBuffer(buffer_size, stack_compress=["obs", "next_obs"],
                              env_dict={"obs": {"shape": (32,32,4)},
                                        "act": {"shape": 3},
                                        "rew": {},
                                        "next_obs": {"shape": (32,32,4)},
                                        "done": {}},
                                        alpha=0.5)

for i in range(1000):
    prb.add(obs=np.zeros((32,32,4)),
            act=np.ones(3),
            rew=0.5,
            next_obs=np.zeros((32,32,4)),
            done=0)

batch_size = 32
s = prb.sample(batch_size,beta=0.5)

indexes = s["indexes"]
weights = s["weights"]

#  train
#  ...

new_priorities = np.ones_like(weights)
prb.update_priorities(indexes,new_priorities)