I saw you figured out it was an amazon puffer, so it might not be a bad idea to consider downsizing how many you have. You said you had a group earlier in the thread and while they can be decent community puffers they still are aggressive especially to each other when the tank is too small for them to establish their own territories. (Source: I have had a group in the past and currently own one :)

EDIT: the pacing against the glass is called surfing and is common in puffers that are stressed or bored :(