After you activate the "Block Receiving Gifts on Channels You don't Follow" setting, if you touch any of the three settings("Hide Progressive Gifter Badge and Gifts Given Count", "Hide Subscription Status in Chat Viewer Card", "Hide Founder Badge") below it, the "Block Receiving Gifts on Channels You don't Follow" setting is therefore disabled.

I had this experience before, so I made an ticket to the support team, but at this time, I couldn't reproduce it because I didn't know the exact cause, so I just let it go.
However, this time, I find the cause and report it.