iPhone 6 keeps waking up every few seconds on it's own

My iPhone 6 suddenly started waking itself up from sleep. Every 30 seconds or so, it wakes up to the enter pass code screen, stays on for a few seconds, then turns off again. I currently have it set to Auto-Lock after a 1 minute. I have tried doing a soft reset but that didn't help. I don't particularly want to do a hard reset, but unless someone has a solution or possible reason, i don't know what else to do. Anyone else had this issue? This is going to be a serious battery life problem!

Side note : I just discovered that whatever is causing this is actually preventing the phone from auto-locking. The screen dims and turns black like it should, but then a few seconds later comes back up but not on the lock screen. If I lock it manually, it locks fine but then starts the wake up/sleep cycle every few seconds again.

Message was edited by: EthansMommy08