copied and pasted your ratings into an excel spreadsheet.
Your 38 rounds used from Run from the Roses last year until now averages 862.82.
The last 25% of your rounds are double weighted which would bring your average up slightly.
Your median is 865.5
Your Mid-America tournament is still dragging you down. 783,786,813
The 807 KCWo 2013 & Might Mo (807 & 817) is recent, so it is being double weighted which is also dragging you down.
Without seeing your ratings from last year that produced 866, my guess is while you have had some really good rounds (942, 926, 924) you have had some really rough rounds that are balancing it out, producing a statically net neutral change.
Also, if you have 1 or 2 really, really bad rounds (i.e. more than a 2 or 2.5 negative differential, the PDGA formula drops them off. So it is actually better to have 1 or 2 just absolutely terrible rounds then 4-5 mediocre bad rounds.
From a statistical analysis perspective, while there is a lot of griping about the PDGA rating system, IMHO once you get above 15-20 rounds, it really is pretty accurate. On a round by round basis, not so much, on a weighted average basis over 20, it's pretty good.
For example, I had my first sub-700 round (689) at NE League at Blue Valley. Am I really that bad? No - long holes just kill me. I also had a 912, 921, and 930 at NE League at Cliff. Am I really that good? No. My 908 at Am Worlds I think is a legit 900+, but I trust that rating more because there were 80+ propagator players being analyzed, and the NE League where I got my 689 had only 14 propagators. That is one of the reasons why they throw out super bad rounds.