I’m not sure how this warning corresponds to the usage of TensorBoard and assume it might be unrelated.
Note that tracing a model uses the provided inputs and records all operations in the model in order to export them. Data dependent control flows and random operations will be recorded in the state they were executed during the tracing.
In your particular use case it seems you are using dropout layers, which are randomly dropping activations during the training of the model in the forward pass.
Tracing the model would record these operations as static ops and the dropout masks would not be resampled, which is why the usage of model.eval() is recommended in the warning message.
To properly record these operations, script the model via torch.jit.script.