Group text alerts keep hiding themselves
I have a group text with 3 other people. Recently, I stopped receiving alerts for this chat thread on my phone.
I clicked on "Info" for the group text and turned "Hide Alerts" OFF.
Later I realized it had turned itself back on.
I swiped left on the group text and un-muted it.
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At first, this seemed to work. But I also sync messages with an iPad. For the next new message in this group, I read and responded to it on my iPad. And then, I noticed the group text was once again muted on my phone.
The muting only happens on my phone, and only with this group text. Do Not Disturb is only enabled overnight, and I can't find anything other settings (Notifications, Messages, or the Contact for each person) that might be causing this problem.
I'm using an iPhone 12 and iPad Air, both running iOS 14.4.
iPhone 12, iOS 14