[bsder]

It was almost certainly over-utilization of a low revenue tier that did it.

Cloud companies all make certain claims around bandwidth/CPU/memory/etc. on low tiers, but if you actually fully utilize the tier, they'll almost invariably make your life miserable.

Normally they won't outright boot you (this seems surprising), but your instances will suddenly always be limited to what the Cloud Company considers to be "proper" for the low tier you are paying for--which magically is always much smaller than what they advertise.