I think they do it on purpose so they don't sound Spanish. It's basically Glaswegian Iberico. When you listen to the Latin accent in France, Italy and Spain, how come that little bit suddenly sounds like Vladivostok in comparison?
As I say, I reckon they spoke the same until 1640 when they became independent again, and just wanted to sound as different as possible. NB This is pure speculation. I haven't read or studied anything even suggesting this.
Let's face it, if your national language isn't even along the lines of your country name then you shouldn't exist. I'm looking at you America and Australia. Scotland and Ireland too.
'Seems that I was busy doing something close to nothing
But different than the day before'
'Met a dwarf that was no good, dressed like Little Red Riding Hood'
'Now you're unemployed, all non-void
Walkin' round like you're Pretty Boy Floyd'
I hope this helps
"Gabon's first confirmed European visitors were Portuguese explorers and traders who arrived in the late 15th century. The Portuguese settled on the offshore islands of São Tomé, Príncipe, and Fernando Pó, but were regular visitors to the coast"
Just like they were swapping bronze for slaves in Benin for centuries. {cf the stunning artefacts in the British Museum.}
But they weren't the colonial power at the time when mass education would have started in the late C19th or early C20th and as such, they wouldn't have left a lasting linguistic impression on the country.
{1st in Imperial history, init?}