When I was messing around with random tick speed and cacti I found out that if you put tick speed above 100 000 then break the lowest block of the three cactus blocks then a random stream of cactus blocks started flying upwards. It had the animation of a cactus block breaking but the cacti was being created out of thin air and then it suddenly broke right after.Youtube
Glitches with high random stick speed values will not be fixed, see MC-177987.