I'm a fan of the new tasks feature, but I found that any task-related activities slowed the Android app down to the point of being unusable. So, I removed the calendar and tasks widgets from the home screen and EN worked OK.
With the 10.19 Android release, performance of tasks on the home screen has improved dramatically on my device (a Huawei P20 Pro). The home screen refreshes in under a second. I can do crazy things like adding tasks, or completing them without them mysteriously reappearing a few seconds later.
The dedicated Tasks screens can still take 20-30 seconds to refresh, but that's less of a problem because I use the Windows application to do most of the heavy-duty task management. When I'm out and about I generally just use the home page, which is now a lot quicker.
So far, so good!