I see a lot of questions in this forum about turning *off* the "organize by conversation" in Mac Mail.
Oddly, I have the opposite problem.
I have to individually that that feature *on* for each individual mailbox, or Smart mailbox. And sometimes it turns off again, even though I've previously actively turned it on. How can I make this setting global for all of my email accounts and all of my mailboxes?
iMac 27″, macOS 12.4
Try this: Reset NVRAM or PRAM on your Mac - Apple Support (for Intel Macs) and Mac startup key combinations - Apple Support (for both types)
If that doesn't help try booting into Safe Mode according to How to use safe mode on your Mac and reboot normally and test.
NOTE: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following;
• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)
• Prevents Startup Items and Login Items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files
organize by conversation
