take time to get at reverse from 4 wheel drive?

How much time does it take to engage into reverse? Is the fluid clean and full?

It sounds like the transfer case shift actuator is getting weak, we should run the codes though to see if any are stored, this guide can help.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is the location of the transfer case shift actuator in case you get codes for it. Check out the images (below). Let us know what you find.