Program not registered as started in task bar

KNXS

I cannot remember when it started, but I am experiencing that when I start Revu Bluebeam from the task bar, it is not recognised as running. If I then open many windows and click the Revu icon in the task bar, to go to Revu, it instead opens a new Revu window instead of going to the original one. The problem has persisted through several updates, and is only resolved once I manually make the Revu window visible, and then clicks in it to "activate" it.