History Erase Problem


We have facing following problem in ERPnext normally for QC & Task.
Erase History after few days.
(like - Assignments, Attachment , sharing & comments)
Please refer following image in that it was created before 15days after create there is some assignment, sharing & one file attachment that history not seems now history seems only Created 15days ago then update seems last 7days only.
15days to 7days between history erased (attachment is present to QC ) but attachment history erase.

Please advice on the same.

@umair @rmehta Please advice on above query.

This has to do with search results being deleted which is somewhat similar to what you report If I create a Contact then delete it it still shows up in Search

Options for more clues, besides search the forum, is to do some experimenting or dig into the code.