Is the system on-line if so, have you restarted (rebooted) the computer
Once done, the update would have been completed.
Of course it is. Rebooted it a couple of times in the last week, still have 18.6.2349 version. I also can not find any newer version above 2349 on the internet. Maybe i understand something wrong?
Do you have the latest
build. Updates happen other than actual program or version updates.
If you have the latest build. then, as stated by Avast, the fix has been applied.