You can, but it depends on when the tick occurs a bit.
I mean you can always just find a different way to get the gametime/frame time.
In worse of the worse cases…
Save GameTime to its own local variable.
Do math of the current value of it - the stored value (before stored value updates).
Thats the time between ticks local to the function.
It’s not necessarily rendering related anymore, but in a BP you usually need the time of the BP tick to sort out what’s what…