Reminders syncing problem with an updated device

[otetzone]

Hello Community

I have a number of iPhones SE OG (iOS 10.2, 10.3 and 12.4) and two MacBooks, HS and Mavericks. And a HomePod OG. This is the ecosystem.

Recently, I had to update the 10.2 SE to iOS 14.7.1 (in order to update APP to the latest firmware, to add an airtag etc). However after thinking twice I decided to register it with a different Apple ID so it wouldn't ruin the working ecosystem. I mean, Apple have already changed Notes and Reminders apps and had I registered this phone with my Apple ID then the reminders wouldn't sync across my other older devices. I'm really stuck with the Reminders app. I can only use this updated phone with another Apple ID and another sim-card to keep everything I have working smooth but man is it a pain. Wish I could downgrade it but obviously you can't downgrade the iPhones.

The Macbooks I have I am not going to update. I just don't want to. I'm fine with what I have and the way I have it except the updated phone. I'd rather buy a new Mac when I get the money rather than updating my current machines. But as for now, does anybody know of any elegant workaround? Is there another server except for iCloud that could help me sync the Reminders across devices no matter what system they're on? Or maybe there's another solution?

I would be grateful to hear your opinions. Just please do not suggest having me uptate the MacBooks. It's not an option. Please. If there's nothing else to do I guess I'd have to sell the updated phone along with APP and an airtag. I just hope the situation is not as bad.

TLDR: Updated iPhone to 14.7.1, the Reminders wouldn't sync across the older devices

 

[NoBoMac]

Yeah, you're stuck, as old Apple ID is "converted" and new Apple ID probably defaults to new format Notes, Reminders, so that won't sync either.

Can explore if there are apps/services that are outside of Apple ecosystem. Or try syncing via a free Outlook account, as they support syncing of Reminders (have not tested or used, so, YMMV).

 

[otetzone]

Well, Outlook/Exchange works only one way. I mean I can make reminders on the updated phone and they show up on the "old ones" but not the other way around although they configured similarly. Maybe it's because the old ones are also syncing with iCloud.

I have a dilemma here. Should I log in into updated phone under my real Apple ID and get handful of problems or use a different one and suffer inconvenience. Not that I was asking this question anyone in particular but I'm afraid to try since there's no going back. I'd "lose" two macbooks, two other phones and a homepod that work in sync now. That would suck. I just don't know what to do. Maybe it's indeed worth to sell the phone with the airtag and the APP altogether just to rid of it and end the problem? It really is a pain.

I also got some New Apple Agreement on the updated phone. After studying the web it turned out that Apple suspects me having two ID's. I wiggled out of the situation but still it makes me bit nervous.

 

[otetzone]

Okay, so far I changed everything from contacts to calendars and of course reminders to Outlook (exchange). Both phones (iOS12 and iOS14) and a Mavericks machine. I'll report how it works because not I'm not sure it's working in both ways. I had to disable everything iCloud on the phones except for Find My Phone. I wonder if it's working well should I then change the updated phone to my Apple ID? Or should I return everything back to iCloud as it was except for the updated phone and have it on Family Sharing? Is it worth it? I just can't decide what would be the most elegant decision.