noindex tag in /blog/ and all rank math settings/wp are right

i got a website.com/blog/ <— that page has a Noindex tag in the source code . i looked on every possibility in rank math settings and they re all ok… and i even went to filter noindex pages and posts and non of them are noindex. but in source code for that specific page it has that tag. and i know it is rank math because when i disabled the plugin the noindex tag disappears. i do not have no cache system. and in reading settings wp “discourage search…” it is unchecked… i have covered it all … i hit the wall right now . any suggestions.

thank you