I came across this issue after converting to Kirby 3. When using character reference entities in links the reference name displays and not the character for example:
(link: https://www.youtube.com/watch?v=ez-2M3C_4wU text: Apple® Pay How To Video)
Will display ® - but if I do traditional markdown like below, it works fine and renders the character as Ā®
[Apple® Pay How To Video](https://www.youtube.com/watch?v=ez-2M3C_4wU)
As an alternative to using markdown links you can enter those characters via the keyboard, in the example Alt+R and they will render alright in the tag.