Thanks for your question. In cats, I believe I any change in behavior can be significant. If you are concerned about it and feel it is different than what is normal for her, I would continue to investigate it. My first concern would also be that her glucose is out of whack as you said. When it is checked at the vet, we are really looking at just one moment in time. It has been reported that a cat's glucose can vary very much from day to day. I wonder if her glucose level is getting too low, making her feel abnormal. This is most likely to happen around 4-8 hours after her insulin check. I think it would be worthwhile to have a glucose checked when she is doing these behaviors.
Could she be bored? I suppose but I would want to rule out a medical cause first. I also feel at 8 or 9 she is too young for dementia. You could also have her blood pressure checked as this can sometimes cause behavior changes although we tend to see this in older cats as well. Hope this helps and that you can figure this out!
