There is a newer form of LTE, LAA, which does use certain 5GHz channels shared with wifi. Those two technologies would share 5GHz channels. This is still rare outside of large event venues, and it is NOT the signals that a cellular amplifier would be amplifying.
Other than that, there should be zero correlation between wifi equipment and cellular equipment. With that said, sometimes analog RF components can interfere with each other at close range. For example if you put two APs right next to each other or put a cellular booster and wifi AP literally right next to each other, it is possible they can interfere with each other.
Generally I recommend at least a few feet of separation (if not more) between wireless equipment whenever possible, but it’s not super likely to have that kind of interference.
Perhaps with your wifi working better with Meraki, more people are using wifi and hence LTE is freed up? Cellular amplifiers/repeaters increase signal strength but they actually reduce the overall capacity of the cellular network.
