I have a 2016 13” MBP for work. I love it. But, when I plug it into my external 4K monitor at home and scale the resolution down a notch, the whole thing slows

I have a 2016 13” MBP for work. I love it. But, when I plug it into my external 4K monitor at home and scale the resolution down a notch, the whole thing slows down to a grind. I also have a Mac Mini (2016) at work and contemplating bringing it home to use with the 4K. Giving somewhat the same spec between the 2 I doubt it makes any difference though. Do you guys have any slowdown experience when hooking up a MBP to a 4K monitor in scale-down mode?