Share your experience!
My XZ1 keeps asking me to update when already have done so ?
Hi @BraddersCOYS, I am sorry to hear about this.
If you have more than one update to install until you are the latest available version, you will get a new notification after each update saying that there is a new update available. This might happen if you have bought an Xperia phone that is not a completely new model.
If you have more than one update pending, you can either install the the software updates one by one, and restart your device after every update, or you can perform a software repair using Xperia Companion and your device will get the latest update at once. Please note though that a software repair will erase all user data, so make sure to do a backup of your phone before proceeding with the repair.
I hope this answered your question. Please get back to me if I have misinterpreted your question or if you need more assistance. 
What version are you running?
For example last week, on Monday my phone updated to 47.2.A.4.45-R3C (also Dec security patches)
the very next day it said a new version was available and it updated to 47.2.A.6.30-R3C (inc Jan sec patch)
Nothing since Oreo / Sept patches and then 2 in 2 days.