EA not recognising Steam install

ohxdebug  Can you currently launch the game through Steam, without needing to repair?  Did you install Sims 4 into the default location for Steam games or create a new folder?  This is the default:

C:\Program Files (x86)\Steam\steamapps\common\The Sims 4

If that's not the issue, please repair the game through Steam (Sims 4 > Properties > Installed Files > Verify integrity of the game files) and launch it once, then see whether the EA App recognizes your install.  If not, please let me know what antivirus you use.