rich text display field in validations not displaying the validation message correctly

To clarify, the "validations" parameter accepts only plaintext (and/or an Array of Plaintext, where each item in the array will display on their own row).

The validation message has to be plain text, the component will do the styling for you. Also if you wish to show custom validation you can also use a!validationMessage() to define validation message for form, section, and editable grid components.