Hi,
I'm really sorry to hear about the problems, but the promised uUpdate fixing this issue in AV 18.5 (at least at our side) was released at the end of August. You can try to check content of the key named "MicroUpdates" in "HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\AVAST Software\Avast" path of your registry. You should find uUpdate number 377=unixtime placed here, if it was already updated.
Unfortunately, this uUpdate doesn't fix the issue in the UpdateProxy.dll in case that you use CloudCare and also the problem with downloading from avast servers in the setup (if mirror is unavailable). However, it should help you with the downloading issue if you use the managed Avast Business Antivirus.
Regarding the AV 18.6 and console 6 which contain all the fixes included: we are finalizing tests of the console 6.0 together with AV 18.6, however, we need to synchronize the testing with the CloudCare and Managed Workplace team. I'm really sorry but I can't tell you any specific date at the moment as we are dependent on the other teams, but I hope it will be soon.