Cannot Enable Find My Network in Find My iPhone settings for iOS 14.2

Upgraded to iOS 14.2 on November 12, 2020. In settings, noticed that WIFI "Private Address" was disabled (supposed to be enabled by default) so I enabled it. Worked fine. Then, in settings/Find My, both "Find My iPhone" and "Send Last Location" were enabled. But, "Find My Network" (previously called "Enabled Offline Finding") was disabled. I clicked the switch to enable and got a message saying additional security software must be installed, clicked OK, then a blank window opened for about 1 second and disappeared. The "Find My Network" feature would not enable.

Anyone else have this problem? Is it a known bug or is there a way for me to fix it?

Note: earlier in the day while on iOS 14.1 (prior to upgrading to iOS 14.2) I took my iPhone to an Apple Store to get the battery replaced. I had to disable "Find My iPhone" for the repair. Afterward I enabled "Find My iPhone." This was earlier than when I upgraded to iOS 14.2. I don't recall the "Find My Network" being disabled. I thought it was working but can't be completely sure.