No screens in the toilet water line eh? Well unless your 2016 toilet model us different that my 2015 model, the tech doesn't know what he's talking about. There most certainty is a screen in mine.
Attached (I hope) is a pic of my toilet water supply line at the toilet. Notice the crap in the line and if you look closer, you'll see part of the screen showing through.
I'd ask them... OK, what exactly (and where) was the problem and what did they do to fix it.
I'd also suggest you unscrew and look at the bathroom sink outlet (where the water comes out) and see if you have crap in there about to plug up that sink.