Can’t post under my username!!!

Something weird is going on. I’ve made a few posts and I noticed that they were posted in the name of my other users (they’re set as authors). In the drop down list of authors to choose from when making a post, my username doesn’t show up. The username is the default admin username. It just doesn’t show up in the lists of authors for a post. In the drop down box of some of the posts that WERE posted in my name, I’m not listed there anymore.

Any ideas? This is really weird. I’ve used WordPress forever and this is just odd.