GUI LogViewer: Stucks upon close

[Technologov]

Host: VBox 6.0.0-BETA2 + Win7 x64.

Steps:
1. Right click on any running VM -> Show Log
2. Save logs
3. Close Log Viewer.

Expected:
Normally it must close instantly.

Actual:
in some cases, I have observed a 5 seconds delay until close of the Log Viewer GUI. WTH? It never happened before. (v5.0 and v4.1.x)