It's barebones, but glitchy?! I've been using it for years, and it's been rock stable for me.
For a long time I thought it was perhaps due to poor sync with the Mac, since sometimes I manage reminders from there, but the same thing happens with the wife's phone and she doesn't sync Reminders. She has a single daily reminder at 10pm. Sometimes it shows up 4 times. Sometimes 4 times and 1 disappears for a net of 3 reminders. Sometimes just 1 shows up. Sometimes none of them show up. It's bizarre.
I've stopped thinking about it as "glitchy" and more "the new Apple way".
Perhaps you should try logging off and logging in again.
I totally agree.