Not sure how true this is, I had my test on Sep 10, it is already October 14 and no Oath yet - more than 5 weeks have passedYour timeline and mine are almost the same .
App sent, delivery are same.
Signatory same Mike
AOR- Feb 19
IP- March 16
Test Invite - May 22
Test Date - June 13
Decision made - June 14.
My observation is that those who had their test in June ,July or Aug will have to wait a bit longer for the Oath but could get the invitation by Dec.
Those doing the test now are given Oath invitation in just 3 weeks time.
The officer had told me in summer months its slow.