UPDATE: It works only when called from Begin Play event, but not from other events or functions executed after spawning!
If you try to disable actor ticking by ‘Set Actor Tick Enabled’ set to FALSE, it doesn’t do anything, actors still ticks. You can test it by e.g. printing a strings from its Event Tick.
I attempted this on my end and it seems to be working as intended. What steps can I take to reproduce this on my end in a clean, blank project with no additional content?
The error you are experiencing is because the actor has not been fully initialized when you run the function. Try adding a delay between the spawn and the function, this stopped the tick on my end.