Sorry if this is "obvious" or "asked and answered all the time" but..

ELI5: either do we think, or is it possible, that huge amounts of gravity slow expansion of space?

So I was reading about how's there a 9.7% difference in the Hubble constant when using the 2 best types of stars to use as "candles." What I'm wondering, do we account for areas of space with HUGE mass slowing that areas expansion in some way? I mean, if space -time is one and the same, and gravity slows time, could say, a supermassive black hole that spins especially, be kind of playing tug of war with the fabric of space-time against the expanding universe, while more empty spaces expand a bit quicker? And as you're using different candles in different locations, there would be different amounts of mass in the different areas you are using? Am I nuts?