State of the post_activation_LSTM_cell is too tricky.
I forgot to set initial_state to post_activation_LSTM_cell so I fix initial_state then run again, but test failed though it’s not wrong (because I passed test later as the same code).
When I initialize it (re-run post_activation_LSTM_cell = LSTM(n_s, return_state = True)
in above cell), this problem is fixed.
I found Troubleshooting Note
below the unit test cell after trying to fix the problem.
It should be above the test cell…