You didn't mention if you were using a desktop device (PC/laptop) or a mobile device, what browser, etc. With all the changes in the mobile version of the site, glitches aren't odd. So it might be something related to that, if you use a mobile phone to post.
Some other issues that can cause questions not to post:
*Submit button glitch. If you can't submit your question try copying what you typed, refreshing the page, pasting your text back in the question/details box, and try to Submit again.
*Question errors out when trying to Submit. Make sure there are no special characters (esp the percent sign), URLs, or image files that could be causing a problem. Spell out all special characters instead of using the symbol. Remove any URLs or images. If the question submits at that point, you can try adding your image or URL as an update, if needed.
*Question exceeded the character limit and needs to be shortened.
*User has reached their limit for posting questions for the YA day (so wait until after Midnight GMT, then the YA day rolls over, to post your question)
*Question Submits but only you can see it. Change the category for the question, wait a few seconds, and then move it back where it belongs. Some posts get caught in the spam filter and that's one way to 'shake them loose' so to speak.