"index contains unexpected zero page" problem

Hi guys,

We face "index contains unexpected zero page" problem in prd postgresql 11
environment

This url shows that need to backup database firstly, is it necessary?
https://cloudblue.freshdesk.com/support/solutions/articles/44001889599-error-index-tablename-contains-unexpected-zero-page

If "create index concurrently" create a new index and drop the old broken
index is a solution to avoid table lock please? Thanks

Best Regards
Dennis