Was a root cause done on that? Was it due to wind power?

Trigger suspected to be one substation https://www.reuters.com/business/energy/power-generation-los... The blackout itself is suspected to be amplified by ren https://montelnews.com/de/news/96607ac1-dd73-4c23-bb47-a7c2a... "Die Experten betonen, dass erneuerbare Anlagen das Problem nicht nur nicht abfedern konnten, sondern möglicherweise verstärkt haben."

https://en.wikipedia.org/wiki/2025_Iberian_Peninsula_blackou...

The root cause is not known, but Spain was producing excess power (primarily solar) at the time around the disconnect. Some fluctations were seen, then supply started to disconnect from the grid in Spain, leading to sudden loss of 2.2GW of power. In Spain, automatic load shedding then happened to try to recover, but it was too little too late as neighboring countries detached from Spain to protect their own grids.

Nothing about this sounds like an issue with renewables.

No, the study is still ongoing. I can't find the link (and Google is functionally useless for finding original links) but Spain's power authority held an update last week where they gave a summary of events (where the failure first happened, where it spread to, etc) and if I understood correctly will have non-Spanish/French/Portuguese experts do the full investigation.

Still a ways away from understanding what happened

https://en.wikipedia.org/wiki/2025_Iberian_Peninsula_blackou...

not strictly because of wind power but few denies that wind power hasn't been a contributing factors - politically it's too sensitive so it's going to be "under investigation" for a long time. Alledgedly too little inertia / rotating power ... there is a parallel to the Australian blackout 10 years ago, where the solution was to build large batteries