NetGuard is blocking a specific IP address (or more than one address) that your PC tries to connect to when these scheduled tasks run. Usually the Netguard block message says what that address is. Can you make a note of it and let me know what it is?
There is always the possibility that your RealPlayer installation has been modified by malware to connect to a malicious site. If I saw this on my PC I would uninstall RealPlayer and run scans with McAfee and Malwarebytes, then clean out any remaining RealPlayer files and registry settings using CCleaner (and a manual check of the file system) before re-installing RealPlayer from the Real.com site.