Welcome to the forum
Your 2018 documents are spread too far apart - you need them to be every 4 months but you have a gap of 5 months between Oct and Mar, and between Mar and Aug 2018.
Also you only need to cover a maximum of 2 years with the documents, so that means from September 2016 to Aug/September 2018.
For example:
Sept 2016
Jan 2017
May 2017
Sept 2017
Jan 2018
May 2018
(added extra Aug/Sept 2018)
Sent from my iPhone using Tapatalk