Specific users cannot access our API during times of the day

We recently moved our backend to GPC using Porter as our PaaS provider, so our APIs are now all in GPC, connecting thru a DNS that is in Cloudflare for obvious reason. Our clients are still in our older provider, but since we moved the API and connected it with Cloudflare some of our users have been noticing degraded performances.

The most common cases are from international users, from Philippines for example, and local US and Canada users but always at around 5-7AM EST, these users literally can’t connect to the API, while all other users connect fine. I am new to Cloudflare so would love to have some directions on how to debug this.