Although this can be annoying or confusing, there is no bug.
Take a look at your Stack Exchange accounts page. Currently it shows:
10 questions, here on Stack Apps, and 1 question on Stack Overflow.
Those are the same numbers currently reported for you by /users/{ids}/associated
.
Both sets of numbers are currently stale (You have 11 and 0 questions), but this is because
Stack Exchange updates lesser-used reports/statistics in timed jobs.
There is too much data for everything to be instantaneous. That Stack Exchange account information takes anywhere from a few minutes to a day to update, depending on the column.
Also, these jobs sometimes crashjobs sometimes crash. So something that normally updates in minutes can occasionally take quite a bit longer.
Check back in a day and see if the numbers are still wrong -- assuming you haven't added a bunch more questions. ;)