No support for `tf.reduce_sum` in Tensorflow Framework?

Provide details on the platforms you are using:
Linux distro and version: Ubuntu 16.04
GPU: Nvidia RTX2070
nvidia driver 418.88
CUDA 10.0
CUDNN 7
Python 3.5
Tensorflow-gpu 1.14.0
TensorRT 5.1.5.0
UFF Version 0.6.3

Describe the problem
Hi, I am trying to to implement a model that utilizes a stagewise regression algorithm.
Like many others, I have generated a frozen model as .pb and am trying to convert it to the .uff format and subsequently the .plan format.

In the model, I have a input tensor of shape [Batch x 3 x 3] that I’d like to perform reduce_sum on as follows:

#input_shape [n, 3, 3]
output = tf.reduce_sum(input, axis=2)
#output_shape [n, 3]

When converting from .pb to .uff, I get the following warning:

Warning: keepdims is ignored by the UFF Parser and defaults to True

So sure, I go ahead with applying a tf.squeeze() to remove the redundant axis as follows:

output = tf.reduce_sum(input, axis=2, keepdims=True)
output = tf.squeeze(output)

Subsequently, when trying to convert the model to .plan using the UFFParser, I get the following error:

[Error] UffParser: Parser error: ssr_function/Sum: Invalid reduction axes

Which still occurs regardless of which axis I attempt to reduce_sum o.n
(Tried axis=1 and axis=2. I can’t specify axis=0 as that is the batch dimension).

I get the same error when using tf.keras.backend.Mean() despite it being listed as a supported op on in the TensorRT documentation.

I think there might be a bug in the UFFparser when it comes to reduce operations as specifying non-batch axes still raise the invalid axes area.

Any help regarding this issue will be greatly appreciated!