There's no way to get an answer to that by posting here. Jams have to be seen by itch.io staff before they show up on the calendar, and the criteria for selection aren't public. The rules of this category suggest other things to try.
Viewing post in GameJam not showing up.
also if I can't get the answer here where would one get it? because it feels a bit inconsistent.
2out of 4 jams have been on the page. one time we got an answer in an email that they fixed it. it worked.
the one after was not on the page. The last one was on the page and now it's not there again.
" criteria for selection aren't public"
I would strongly suggest this should be public so others don't get the impression that there's some prejudice going on here.
...Please read the last point again:
Please do not create topics asking how long it will take for support to reply to you. Different questions may take different amount of time to respond, typically we will respond within a 1-3 days but it may take longer depending on the type of issue. If you haven't already, search for existing topics or check to FAQ to ensure that your question has not been answered elsewhere. To ensure that you request is tied to your account and prioritized appropriately, please contact us using the email address you have connected to your account. If you still need to make a topic about a Support Request, you must include your ticket ID with your message.
Hope this helps.