hmm, the following code works for me locally. Can you try this in your dev env?
import torch
from torch.multiprocessing import Pool

def func(net, d):
    out = net(d)
    print(out)

if __name__ == '__main__':
    net = torch.nn.Linear(2, 2)
    data = torch.zeros(2, 2)
    with Pool() as pool:
        pool.starmap(func, [(net, data)])