Restart the services CCMExec on clients and SMSExec on the server - those are the core SCCM/MECM processes.
IISReset is another possibility to recycle all web services.
Under Site Status, there's a Configuration Manager Service Manager utility which gives you granular control. See: 4 Ways to Restart SCCM SMS EXECUTIVE Service.
The Software Update Point role is the main WSUS integration, and there is a WSYNCMGR process which runs to sync the catalog. You can look at these logs to see what it's doing:
D:\Program Files\Microsoft Configuration Manager\Logs\wsyncmgr.log
D:\Program Files\Microsoft Configuration Manager\Logs\SMS_ISVUPDATES_SYNCAGENT.log
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