Everything on Earth is moving, and its complicated.
Lots of different things are going on. Where I live, there was a huge glacier which finished melting around 10,000 years ago and because land farther to my northwest is now going up, freed of all that weight, where I live is now apparently going down, just a little bit. And of course, 'sea level' is rising too, an arbitrary water level of the oceans, not meaning that mountains are getting shorter, just the water level is rising. And of course there is plate tectonics.
Sinkholes might be happening because of removal of a supply of water or pumping of water out of an aquifer? Ingress of fresh water likely keeps the ground up to some extent, even though that sounds a bit strange. If the ground is porous and the water that supported its volume was removed, some parts of it might get smaller. Just a guess.
I'm sorry, I don't know what i2c address the Packrat Arduino code wants for its LCD display because Ive never used that code personally.