Intermittent stalling.

Since sometime around the 3rd June we've had issues with some users intermittently experiencing connection issues while using our site. The requests that fail often never make it to the server, they either fall under "Stalled" or "Initial connection" in Chrome and the issue only seems to affect certain users, possibly those using British Telecom as their ISP, although we've had some reports of users in the Phillipines having the same issue. Using a VPN completely fixes the issue, and it seems to be browser agnostic. Unfortunately it looks like we'll have to disable/move away from Cloudflare, but I wondered if others have experienced anything similar? Thanks!