Blueprint does not work properly unless i am actually looking at it

I don’t even know where to begin to solve this issue. I initially assumed it was an issue with the blueprint itself, but when i am watching it and running the game, it works flawlessly, but when i have it in another tab or not open in the editor at all, it seems to not do math correctly.

This is the blueprint in question: Screenshot by Lightshot

The expected result is that when the player is flying, their speed increases until it caps, then when the player releases the flight key, they begin to fall.

The current result (when I am not looking at it) is that the players flight becomes extremely slow, and will continue to slow till the player stops climbing in height. Moving side to side will make small increases to the speed.

I feel it may be a bug of some kind, since this issue can even be reproduced while the game is running. If the blueprint is closed and i run the game, then tab out and open the blueprint, it will fix it WHILE the game is running.

Edit: Video of the issue https://www…com/watch?v=&

Are you doing anything on Tick? This may just be an issue with very low frame rate when the window isn’t active.
In editor settings there’s an option: Use Less CPU when in Background. You can disable that to see if it fixes anything. Also try entering stat fps and see is there a notable drop in framerate when you are tabbed out. If this is the issue, you will need to incorporate world delta time into whatever calculations are being done on tick, to make sure they will work no matter what the framerate is. At extremely low framerate that can become difficult though.

I am not having frame rate issues, and i am using a delta second node, but the blueprint using the deltasecond node is not being used in the part of the blueprint that has the issues