I've never made this specific effect before, but it kind of sounds like...
First, they ran the vocals through a telephone eq filter
Then there's either going to be a glitch effect on the vocals, or maybe there's some sort of fade that is connected to a trigger so that they can get the rapid cutout of the vocals.
There used to be this really great free plugin that was a VST that added randomized glitch effects to whatever track you played it on and I couldn't tell you the name of it, I just, I remember it being "glitch 1.3", and it had made sounds similar to these, Which is why I'm thinking glitch effect, but I don't know who made the glitch VST or where you can find it now.
I think on the StrxwberryMilk one, they then actually put an echo effect over the clipped vocals afterwards