There is something like a 10 second delay after saving a chart where the messages won't refresh.
This takes about 4 seconds for us. This has been one of the slowest aspects of AC for some time (going back at least to V5). A 4 second delay for sign off never seemed to bother me, I guess because at that point I am ready to take a breath. (As opposed to when I am clicking from box to box, or in and out of charts when I would like things to be instantaneous). This is an area where a little slowing is not a big deal (to me).