Hello,
I have found where the issue is – I have to set it directly from Cloudflare for it to reflect on W3TC’s Cloudflare Extention.
1. Login to Cloudflare
2. Select Caching App
3. Select Configuration under Caching App
4. Scroll down to Browser Cache TTL
5. Select your preferred TTL.
6. Purge Cache
From there, it will reflect on W3TC’s Cloudflare Extension.