this wood is somehow like rubber. its not something my ash backings usually do
rubber is a good analogy. when I tillered a similar combo, I accidentally created a short section on each mid-limb that took a permanent set. otherwise, it seems to do like yours and eventually recover. I would have to bandsaw the bow apart to see if the areas of permanent set was created in the belly or the back.
seeing if the bow progressively slows (thru the chrono) as it is shot more would be interesting. and if you can set it aside and get the speed back next week.