I am currently on 1.15.2 but I think this will affect future versions. When two pistons either side of a sand block extend under the sand block interchangingly (one extends at the same Time as the other retracts) the bamboo/cactus/sugarcane can grow 12 times faster than the old 'zerotick method'. If you removed zeroticking, this should be removed too. Some versions put minecarts or boats inside the sand too.

Watch https://youtu.be/bjcJSj9sMOI