DisableConcurrentExecutionAttribute not work

I have async Task method (not static) in my console app (postgres db) that runs every minute.
Despite the fact that I use the DisableConcurrentExecutionAttribute with a timeout of 60, I see several running copies of the task that have been working for more than a minute. In the logs, I see that they really work and conflict with each other because parallel processing is not supported in my logic.
.net 4.7.2

Reproduce the reported scheduled async Task behavior in the console app setup, using PostgreSQL and .NET 4.7.2 with DisableConcurrentExecutionAttribute and a 60-second timeout. Observe the logs while the task runs longer than a minute; done means determining why overlapping copies occur and confirming that the concurrency behavior matches the intended constraint.

Written by the indexing model from the issue text.