Hi Ken,
Maybe Khan can?
Khan Academy
The freely available online resources these days are legion. Blows my mind how anyone anywhere in the world, with a few closed society exceptions, now can access top-notch learning resources to follow so many paths of enlightenment. Just last night while I was working on some servers I watched a 4 hours podcast between 2 neuroscientists discussing the endocannabinoid system and how it encourages or inhibits neuron communication in the brain. Fascinating stuff that used to only be available in high-level post-grad research lectures. Yet there I was, thousands of miles away sitting in a remote Costa Rican village on the edge of the jungle hanging on their every word and even taking notes... jajaja.
That being said, many public/private school physical teachers in Costa Rica do tutoring on the side. And many of the more educated/dedicated teachers are fluent enough in English to do that even if English is not their native tongue. You may find an expat like Joe teaching on the side. But don't discount the native teachers if you don't find what you are looking for. Asking around the local high-school will likely find someone to scratch that itch.
Another tree to bark up, would be personal video classes. One-on-one, or one-on-several, classes via Zoom can be a pretty good way to go for older kids. Here are a few examples of that in no particular order:
I've used some of those, both with our kids and for personal enlightenment, to varying degrees of success.
I hope everyone got off to a good and safe start to the new year!
Sam