Can anyone confirm the flaw of postgres and how to deal with it?

I loaded several tables onto Postgres.

When you view, you can see all columns.

However, there are 'ghost columns' that I remember I used before, but not
now.

select column_name::text from information_schema.columns where
table_name=a_table

keeps listing columns that I can not see in the current table.

Why does this happen?

What is the solution?

Regards,

David