My Spanish is getting better these days. I’m attending/ I attend a class every Saturday.
There was one disturbing thing I stumbled upon during class. Just like the rule, usually I’d opt for I attend, however given the context, as in the first sentence wouldn’t it act as a modifier and make it I’m attending, bearing in mind that the first sentence hints at something that is taking place nowadays?

Question

Answer

You're right. In this sentence, 'these days' means 'at the moment': you're probably referring to the current period of a few weeks or months, and you're talking about ongoing progress during this period. This period of improvement is temporary, and we presume that the weekly lesson is also temporary: you didn't take a weekly lesson before, and you might even stop taking weekly lessons as soon as you're fluent. So yes: the present continuous is a good tense to use here.