For context, I was making a tweak to GReyes' answer on this question, just cleaning up some formatting with the trigonometric functions. Specifically, I was turning arctan to \arctan and tan to \tan in the MathJax code.
Below is the code in the post and the preview that resulted (blue boxes highlighting the relevant bits):
In short, the functions in the preview become sine/arcsine functions instead of tangent/arctangent.
On playing around, I noticed this does not happen if I instead put \cos or \arccos, or \sec, \csc, or \cot. Only \tan and \arctan would render as sine and arcsine.
What's more intriguing - and confusing! - is that this glitch seems localized only to this question. Playing around on other answers (obviously not saving my edits), I can't reproduce the effects of the glitch. But, another answer to that same question has the tangent/arctangent functions rendering as intended - though on opening it up to edit it, the same glitch arises without me so much as changing a letter!)
Yet other questions that involve tangent/arctangent functions don't seem to be affected: this one and this one for example.
Does anyone have any idea what might be causing this glitch? I feel like it might just be something on my end, but I honestly don't know.
I admit that I don't know MathJax/LaTeX particularly well - I'm terrible at programming and coding in general, and only know what I do of these from experience and seeing other posts - so maybe there's something dumb I'm overlooking. In which case if this is just a waste of time, sorry.