Due to changes in public repository new download URLs and token are needed.
For more information please see VCF authenticated downloads configuration update instructions
After you apply changes status in Lifecycle Manager > Settings > Patch Setup is constantly in Validating state
vCenter 7.x
vCenter 8.x
After changes in URLs vCenter needs to be able to reach public repository and validate token
To test connectivity open browser and use following to test connectivity with your token
In example
https://dl.broadcom.com/<Token>/PROD/COMP/ESX_HOST/main/esx/vmw/vib20/bmcal/VMware_bootbank_bmcal_7.0.3-0.135.24585291.vib
You can use different VIB available in support portal.
If VIB is downloaded that means that you can reach repository and that token is valid.
If nothing is downloaded then review your network setup and firewall and make sure that new URLs are allowed.