Problems using completion with group of tags and regexp

[General discussions about Org-mode.]

Hello,

If I use a group of tags, like #+TAGS: [ ORG : {.+ORG} ], when I use C-c C-c 
for autocompletion, it gives me strange candidates. For example, it doesn't 
offer the tags I'm using in the buffer, and instead, it offers others like:
:endgrouptag, :startgrouptag, :grouptags, :ORG, :{.+ORG}.

Vanilla Emacs 29.3

Best regards