I’ve just seen this:
Has there been any reports accounting for these outages?
I don’t know if it was in the original BBC news item above but now it says
"Cloud computing provider Fastly, which underpins a lot of websites, said it was behind the problems.
The firm said there had been issues with its global content delivery network (CDN) which it was fixing.
In a statement, it said: “We identified a service configuration that triggered disruption across our POPs (points of presence) globally and have disabled that configuration.”"
This looks like the definitive explanation.
If you are in Vietnam you will see cable breaks very often