Custom Fields : Not found in page designer

Have you tried below steps as mentioned in the below community thread?
 

Can you try to refresh the cache with below steps

1.        Refresh Language cache ( from IEE)

2.        Refresh Dictionary cache ( from IEE)

3.        Login to Aurena client

4.        Change the browser URL appending below URL path – note that you must change the existing URL only after “main”.

…/main/ifsapplications/projection/ClearCache?METHOD=CLEAR_PROJECTION_CACHE&VALUE=*

5.        Hit “enter” key to go to that URL – it will return nothing, that’s normal

6.        Now change the URL again appending below URL path – again you must change the existing URL only after “main”.

…/main/ifsapplications/web/server/clearmetadatacache