Customizer not working

Hi there. I’ve recently create this new blog of mine https://happytummyhappyfeet.wordpress.com/ and chosen “Adelle” as my theme. However when I use the WordPress customizer to change my color and font nothing changes. The customizer bar just stucks at “saving changes” for ages and when I refreshed my blog again it is still the same original theme. I tried many many times but the problem still persists. I do want to customize the theme badly because there are a lot of choices that really looks good. Can you help me see this problem through? Thanks so much!

Kwishan