Qralloq says:
PHB 193: "you can take the Ready action on your turn so that you can act later in the round using your reaction."
I would take that to mean that if your Ready action delays part of your action to be "during" an opponents action, then it doesn't change your initiative.
true however what i Always have interpreted is that when you take the ready action, you ONLY get an action, no movement, no bonus action.... ONLY an action.
If you want to take an full turn, so with movement, and bonus action, you have to "delay"your entire turn, in fact changing your initiative.. and to balance it out, i made it that it becomes 0 so that you cannot go from 25, to15 and then later changing it again