for a while now (at least back to 6.04.01, which is the earliest I've kept, then if you
load 2+ characters, then
Select PC1, switch to character sheet tab (OK)
select PC2, switch to character sheet tab (OK)
select PC1 - no change in display until you may some other change
if you load more PCs, it's the same: so long as the previous and next PC have Character Sheet previously selected, then the act of switching characters alone does not repaint the Character Sheet - you must do something else (eg switch tabs and back, switch equipment set, ...)
Windows 10 64, and earlier
confirm fixed