Strange behavior in current Keras setting (tensorflow-1.7.0 Keras-2.1.5) when using CPU After reinstalling Keras and Tensorflow on a Virtual Machine, I have noticed that models fail to train correctly (at the very least those I have checked). 
For example, taking this code from the Keras blog as a test case, instead of decreasing loss and final validation accuracy of ~0.8, loss quickly increased to ~7.5 and accuracy stayed at ~0.5.

It should be noted that when I tried it with older versions of Keras and Tensorflow (on the same computer), I did not observe this aberrant behavior.

I have repeated this experiment at three other setups in which the same behavior was observed - a two other computers using a VM, and a third computer, this time a laptop with no suitable GPU. 
On the other hand, trying this on two computers with GPUs, the training progressed as expected, with loss decreasing and accuracy increasing to the level advertised in the Keras blog and observed with the previous versions of Keras and Tensorflow while using a CPU.

From the evidence I can speculate that either Keras's or Tensorflow's interaction with the CPU was changed in a manner disrupting the training processes. 

Has anyone here faced a similar problem? 
What can be done to solve this?
I recently had a similar trouble with porting working models to tensorflow 1.7. I found that the initialization was the culprit. Adding 
model.add(Dense(2048, activation='relu', kernel_initializer=initializers.glorot_normal())) instead of model.add(Dense(2048, activation='relu')) fixed the problem.