Support says to open a topic here, to suggest the thing.

This isn't happening before 3.4.4 and i find ABSURD that the content under the spoiler tag is being showed in the fast editor if the text is quoted. it's unbelievable it is intended to work this way.

The support team says:

Hello,

Thanks, I see the issue now and unfortunately that is intended. For BBCodes that don't include their own editor styling and just display the raw tags when you add it (such as the spoiler tag), it just displays the raw BBCode itself, including the contents (the hidden text in this case).

I'm speechless.

maybe i've posted in th wrong forum, i've opened id in the ip board forum now. you can close this one.