What you were expecting to happen, and what actually happened:
Waaaaay back in the day, Sirrian told us that Guild Wars battles counted as PVP battles in virtually every respect. We certainly get PVP points for winning them on offense, and they appear in our weekly PVP stats on offense (see above screenshot; I have not been able to do any PVP this week besides today’s Guild Wars battles).
However, defense appears to be another story. My defense team went a respectable 4 for 11 today (better than I am used to, actually). I have only been credited with a single PVP loss so far this week—and that sole defense appeared after I had finished my Guild Wars battles. It does not seem as if Guild Wars defenses are counted as PVP defenses.
How often does this happen? When did it begin happening?
I have never done so few PVP matches at the start of a Guild Wars week, so I don’t know if this has been happening for a while.
Steps to make it happen again
As far as I can tell, the steps to reproduce it are simply to do Guild Wars without having done traditional PVP during the week.
On my alt this week, I had done 1-2 traditional PvP Battles prior to the start of GW, and did have GW Defence battles show up both on the Stats screen and in my Battle Log, by contrast.
Would perhaps be interesting to hear from other people who had done no PvP prior to receiving Defence scores in GW!
I have found that GW defense victories (or losses) will not register in your stats or in the PvP battle log until you have at least 1 ranked PvP fight for the week. This can either be a regular ranked fight or a GW fight. After that initial fight, the victories and losses should register normally. This “glitch” has been around for a very long time.
I believe it must be tied to how regular ranked PvP defenses are registered. I have gone an entire week doing only casual PvP and not have a single PvP defense victory (or loss) register in my stats. As soon as I do a single ranked fight, defense victories (and losses) start registering.