Reminders won't upgrade

Can not for the life of me figure out how to upgrade my reminders list.

Up until last night I've had my iPhone 11+ (running 14.3) and MacBook Pro running Mojave. Then, after learning that my MacOS had to be—at minimum—Catalina to upgrade my reminders I went and finally installed 10.15.7. However, when I returned to Reminders (on any device) it's still asking me to "Update" which when pressed spins a bit, disappears and then comes right back and doesn't seem to have updated in the slightest.

I've tried both fully signing out of my iCloud account on the laptop or un-checked reminders on my iPhone, restart and then check back in but nothing seems to rectify the problem.

ADDITIONAL NOTES:

1. I noticed on my wife's phone—which is also running the latest IOS—that she has icons that she can asign to the reminders and that a share sheet pops up rather than a search filed which shows up on my phone.
2. I did click on a reminder invitation that my wife sent me via messages and it did pop in for a second, but then quickly disappeared and hasn't shown up again.
3. (I don't want to upgrade to Big Sur just yet as I hear it's been having problems running Adobe Programs, but the articles I've read say that I shouldn't have to be on that OS yet.

Any insight, suggestions to rectify this would be greatly appreciated. Thank you.