Can you give more information about the error?
Here are some examples and as we can see that these code can work well.
tensor_list = [torch.randn(2, 3) for _ in range(5)]
tensor_list
Out[9]: 
[tensor([[-0.6082, -0.9290, -0.4921],
         [ 0.3344, -0.9338, -0.8563]]),
 tensor([[-0.3530, -0.5673,  2.6954],
         [ 1.5262,  2.3859,  0.3481]]),
 tensor([[ 0.5392,  0.9646, -1.5962],
         [-2.2931,  0.6707, -0.4896]]),
 tensor([[-1.3532, -0.5953,  1.6039],
         [ 0.2937,  0.3643,  1.3153]]),
 tensor([[ 1.1544,  0.7681, -1.0410],
         [-0.1305, -0.8855, -0.3516]])]

import functools
functools.reduce(torch.max, tensor_list)
Out[14]: 
tensor([[1.1544, 0.9646, 2.6954],
        [1.5262, 2.3859, 1.3153]])

max_tensor = tensor_list[0]
for tensor in tensor_list[1:]:
    max_tensor = torch.max(max_tensor, tensor) 

max_tensor
Out[19]: 
tensor([[1.1544, 0.9646, 2.6954],
        [1.5262, 2.3859, 1.3153]])