Tensorflow "name is not defined"

Question

I'm using TF 2.8.0 on ubuntu linux in a jupyter notebook on a gtx 1660 gpu. The model seems to work fine until I change the name of a simple variable. This line was:

HP_NUM_UNITS_ONE = hp.HParam('num_units', hp.Discrete([8, 16]))

however switching this to another name, for example:

HP_NUM_UNITS_ONE = hp.HParam('jam', hp.Discrete([8, 16]))

now it throws this error in the grid search running of the model

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Input In [12], in <cell line: 3>()
      5 for dropout_rate in (HP_DROPOUT.domain.min_value, HP_DROPOUT.domain.max_value):
      6     for optimizer in HP_OPTIMIZER.domain.values:
      7         hparams = {
----> 8             HP_NUM_UNITS_ONE: jam,
      9             HP_NUM_SEC: stuff,
     10             HP_DROPOUT: dropout_rate,
     11             HP_OPTIMIZER: optimizer,       
     12         }
     13         run_name = "run-%d" % session_num
     14         print('--- Starting trial: %s' % run_name)

NameError: name 'jam' is not defined

Are there some sort of naming conventions or restrictions on what these variables can be called, or what they can not be called. I need to use different names to set the number of nodes for different layers. I have restarted the kernel, and reloaded the whole notebook many times but still get the same error. Thx. J