Checklist disappears on iCloud notes when accessing from Edge/Chrome/Firefox

I love the Notes function in iCloud because I can use it across multiple devices. However last week, when I was updating my notes on my laptop, the checkboxes had disappeared. I was using Microsoft Edge. I then downloaded Firefox... no joy. Then I tried Chrome, that worked for a short while but then they disappeared off that also. I am on Windows 11.

I have ADHD, so the notes function is an essential part of me organising myself. Please can someone help.