native speakers make spelling errors more often than non native speakers because they learn to speak the language way before learning to spell, which means homophones can easily register as the same word in your mind for years before you even encounter the words in writing. having to unlearn things is usually harder than just learning it in the first place.
I've noticed over the years I never used to make the mistake, but the better my proficiency, the more I started making the mistake. I think when you start running on autopilot mistakes like that are made more often
This is a great signal to be careful about! Thanks. Something like a momebmnt when phonetics begin to take precedence on grammar. You don't think that much when speaking and new mistakes appear.