I attempt to run a scan. The first attempt completes instantaneously. I repeat the attempt to scan and the scan runs to proper completion.
This issue affects Avast free 19.7.2388 on Windows 7 and Windows 10. I am not using Avast free 19.8.2393 because of Core Isolation issues.
When attempting run Smart Scan, the Browser Check runs properly but the AV scan does not. It does run at the second attempt.