When your videos reach some of your platforms but not others, the cause is usually the connection or settings for the platform that's missing posts. Check these in order.
Auto Posting doesn't post to YouTube
Auto Posting, with either Random Times or My Schedule, posts to Facebook and Instagram only. If your auto-posted videos aren't reaching YouTube, that's expected. To get a video on YouTube, post it manually and choose YouTube as a destination.
Make sure your accounts are connected to Scaled Creator
Linking your Instagram to your Facebook Page isn't the same as connecting both to Scaled Creator. Both need to show as connected on your Accounts page. A common case is an Instagram account and a Facebook Page that are linked to each other while Facebook was never connected in Scaled Creator itself, so videos only go to Instagram.
If Facebook is missing, it has to be a Facebook Page, not a personal profile. If you don't have one yet, here's how to create a Facebook Page. For more help, see Cannot Connect Facebook.
If Instagram is missing, it has to be a Professional account. Here's how to switch your Instagram to a Professional account.
For more help, see My Instagram Is Not Connecting.
Reconnect the platform that's missing posts
Instagram and Facebook connections expire every 60 days, and can expire sooner after changes to your Facebook or Instagram account, such as a new password. That means one platform can stop receiving posts while the other keeps working. Open a private or incognito window, go to your Accounts page, then disconnect and reconnect that platform.
For more detail, see Why Did My Instagram or Facebook Connection Expire?
Check your Auto Posting settings
Make sure Auto Posting is on in Post Scheduling.
On Random Times, check the daily posting limit for each platform in Post Settings, under Automation. Manual posts also count toward that platform's limit for the day.
On My Schedule, check that your time slots include the platform that's missing posts. A slot set to Instagram only won't post to Facebook.
Here's how to schedule your posts.
Check where you sent manual posts
When you post a video manually, you choose the platforms under Post To. If you only selected one, the video only goes there. If you've saved your defaults, check that they include every platform you want. Here's how to post a video manually.
If a platform still isn't receiving posts after these checks, email support@scaledcreator.com with the title of a video that didn't reach it.