This could be due to the fact that variable holding the training data is consuming alot of cpu memory in the background and hence making it some worth difficult for computation in the training process
It’s like trying to copy a file of 2GB in a hard drive with only 2.1GB of free space compared to a hard drive with 6GB free space
If u’ve coded in assembly b4 u’ll most likely know what I’m talking about.
Hope this helps.