Code-generation support for LSTM networks using ARM Compute Library was introduced in R2020a. Further, predictAndUpdateState is also supported for ARM Compute Library in R2020a.
Please find the release notes attached:
The link referenced in the question links to the R2020a documentation, hence you may have noticed that all the layers are supported.
R2019b included LSTM network code-generation support only for GPU target using cuDNN library and GPU Coder and did not include support for predictAndUpdateState function.
Would it be possible to upgrade MATLAB to R2020a to leverage these new capabilities?
Please note that code-generation for LSTM Networks using ARM Compute Library requires ARM Compute Library Version 19.05.