CF cache slows down site

Hello. I have recently had my site optimized for speed. The speed is very good but every now and then it turns into red. Then, once I clear my CF cache, the speed is green again.
My site is

How can I prevent CF from showing a slow version? I have set browser cache TTL to 2 minutes but that didn’t work.

Hi @hungryinthailandoffi, what is this application which turns red?
Does that application give you more details on what is causing the issue?

If you can see the details, can you compare it with when the site is green?

Thank you.

Hey. After turning off Automatic Platform Optimization the issue didn’t come back.

I do however have another issue. Since several days, many of the images on my mobile version seem bad quality. Could this also be related to CF, or is there anything that could fix this? Thank you.