IMDB & WIKI gender dataset not converging

I’m working on gender detection with 3 datasets IMBDIMDB & WIKI consist of more than 500K image and IMFDB about 3000 images, when using all datasets together model not converging, in case of using imfdb dataset only model reach 90% accuracy, in case of wiki or imbd dataset model not converging, in case of using subset of wiki dataset to be same as imfdb (about 3000 from wiki) model still not converging, what is the reason for this
colab notebook