Markdown details not collapsing/expanding

markdown details

I have recently noticed that when I create a md file or open a System information/date.md file that the [details=“Title here”] is simply displayed as is

as well as <summary>

shows <summary>

in any editor.

Is this a local setting or what.
currently running NC 24.0.1.12
Plain text editor 2.14.0
Markdown Editor 2.3.6