ZM4 Contimuun Energized Bolt.

Good question — there are often specific drop rules for special items like Energized Bolt cards.
Usually, whether a map or mode (like SOS on the new ZM4 map) can drop those cards depends on the event settings defined by the developers. Not all boss boxes or maps are guaranteed to drop every special card.
Also, some events have a per-account limit on how many Energized Bolt card parts you can obtain, which might be why you sometimes see the message that it’s “impossible to get” more — it often means you’ve reached the limit for that account or that box type.
If the official event description doesn’t list the drop conditions or limits, it would be good to ask support for clarification — that way everyone knows exactly how the rewards work.
Hopefully we get a clear answer soon!