Blackboard Value not updating correctly

I got a problem with a string value as a Blackboard Value. I got the string value defined as “StringKey” in my Blackboard. When I let an actor spawn, and try to set the “StringKey” value, it sometimes works, sometimes doesn’t. When I hit play, the first time, it sets the value correctly. If I stop the game and hit play again, it doesn’t. When I am waiting for let’s say 5 minutes, and try again and hit play, it updates again correctly. I am a little confused, why it does sometimes update correctly (the first time and the times after I haven’t hit play in a while) but most oft the time when i repeatly try to play, it does not update?
The blueprint image is my Level Blueprint. This is the only time I am updating the value. I tried and started over with a fresh value, just set it here… same as above…

Maybe someone had the same problems before?
EDIT: Tested it with int and name values. No problems, both are updating correctly every time. Doing the same with them as I do with strings.

I’m also having this issue, 10 months later. Similarly simple setup, int value updates just fine, string value does not.