WSUS downloading unwanted updates from MS which are not selected in Options

It seems, that your WSUS database is some way damaged. For managing WSUS there is wsusutil.exe program. Backup system state with all WSUS files before doing anything, also backup WSUS database with wsusutil.exe export. Completely remove WSUS. Install the last WSUS version, configure as you wish. Restore saved WSUS files to some location, make wsusutil movecontent. Then make wsusutil reset. This probably will prevent WSUS from downloading all updates again. If everything is OK, run Cleanup Wizard to remove unnecessary update files. If this hack doesn't work, you have a backup