Posting the same content everywhere is fine. Posting it in a way that ignores each platform's format is what hurts.
Prepare a post that travels well
Write the main text so it works without the platform's context: a clear first line, one or two supporting sentences, and a link. Avoid platform-specific mentions or hashtags in the shared version.
Add an image or video if you want to reach Instagram and TikTok, since both need media. Use a format that crops well, such as a square image or vertical video.
Connect the accounts and publish
Create a zedgad project and connect each social account once. Then open the compose screen, add your text, link, and media, and tick the accounts the post should go to.
Check the per-platform previews, then publish now or set a time. Long text is split into a thread on X automatically.
Check the results
Open the project log to see the result for each platform. A success means the network accepted the post. An error shows the platform's reason, such as an unsupported video length.
Fix the cause and post it again to that platform. After a few posts you will know which formats work everywhere.
Key takeaway
Write for no platform in particular, add media that crops well, and check the log after publishing.