Until now, had no idea you can’t use a dash for a post file name. One of my post files name contained an underscore _ instead of a dash -. That typo (?) caused the post to never appear—without any error message.
new_post.md won’t show
new-post.md will display the post correctly
is this a post with the date in it? posts have to have the date. A dash - is certainly ok. I don’t remember using an underscore _ but find it surprising it won’t work. Are you sure it isn’t a future date issue? sometimes if you make a post with todays date it is actually tomorrow and doesn’t show up.
The post used the classic naming approach year-month-day-title.md with the current date. Using an underscore (originally a typo) instead of a dash, the post disappears locally and in production. This was odd, but low-key noteworthy.