I never use a glue block on end grain., and I seldom use a glue block,
but if I do and the wood is dry when roughing out (very seldom here),
I'll use hot glue, or CA, make sure the glue gun has heated up real
well, before you use it and I usually will heat the wood as well with
a heat gun, then put on the glue, twist, and clamp.

The foregoing is to much of a hassle, so I use CA more often, I will
put on the thin CA an let it soak in and harden, after that I use the
thick CA and clamp, and let it sit till it's hard, sometimes I will
spray some accelerator on the seam if I don't trust it.

AND Before you start turning give it a real good tug, so you know it
will stay on.

One more thing, almost always, I will have a shallow tenon and
mortice, to align and for greater strength of the joint.

Have fun and take care
Leo Van Der Loo