There are several videos available for learning this stitch, but I wanted to have my version accessible for my students. I demonstrate it first with extra large yarn/hook so that you can see the stitch anatomy easily. Then I switch to a worsted weight yarn for a more conventional view. I also include a tip on how to keep your work from curving.
Have you been losing stitches when crocheting in the round? Most likely, the cause is improper joining. It can be confusing for new crocheters to determine where to insert the hook to join double crochets made in the round. It is helpful to remember that when you are looking at the front of the double crochet stitches, the loop is to the right of the post. Don’t make the mistake of joining the last stitch to the loop of the second stitch instead of into the beginning chain-3, which as you know is the first stitch of the round (unless otherwise specified.) Hopefully these photos will clarify it for you.
Look for the third chain of your beginning chain-3. Notice the difference between it and the loop for the next stitch.