Check out this link: https://knowledgelayer.softlayer.com/articles/auto-scale-terms#status
Scaling: Used when any members are not yet provisioned or have an
active provisioning transaction running. In scaling status, an auto
scale group cannot be triggered for scaling and only non-actionable
properties can be edited.
Busy: Used when any members have an active
transaction but the transaction is not a provisioning or reclaim
transaction. In busy status, an auto scale group cannot be triggered
for scaling and only non-actionable properties can be edited.
Suspended: Used when a member is not scaling or busy, but has been set
to Suspended. In Suspended status, an auto scale group cannot be
triggered for scaling; however, any property can be edited. Any
actions that would occur as a result of a group create or edit don't
occur until the user resumes the auto scale group. An auto scale group
can be suspended manually by the user or automatically if there is an
error scaling the auto group for any reason. An auto scale group can
only be resumed by a user.
Active: An auto scale group is active if it
is not scaling, busy, or suspended. When active, an auto scale group
value can be edited and all triggers can be invoked.
This is the documentation available about the status, that information could help you to understand better what is going on. If you see scaling is because there are provisioning proccess runing (It could be because your VM is very large and the provisioning takes long time, there are several members which have provisioning proccess running, the provisionings have not been approved yet).
Suepend is for any error, such as when the datacenter does not have enough room, the provisioning has failed or such as the reasons you mentioned, it could be several reasons for an error and there is not any documentation about all the reasons.
Regards
