Offline bloggers and tags

I’ve tried using Zempt and w.bloggar as offline utilities for blogging. The problem that I’ve encountered with both of them is that when, for example, I insert link tags in my post, some of the characters are converted to their ASCII designation but the character stays.
Hard to explain but here is an example:
if I put in a “<” for a tag, the view os the post on the site comes out as “<<” and the html looks like <<.
Has anyone encounetered this and maybe have a workaround?
TIA