Not really certain what you're describing, but generally speaking you have to first generate the LOF, then insert a line before its first entry and type your heading in it and apply whatever tag needed to format it. Regenerations do not remove the title.
If you want to add more tags to be included in a generated list, you have to do it through the Set Up window. Simply adding a new tag to the paragraph catalog won't add it to the "tags I'm looking for" list that Frame uses to pull information into the generated files.
You should not add "TOC" or "LOF" to the end of a tag name or manually create the *TOC/*LOF/*LOT tags. Frame does that automatically when you generate the file for the first time, then you edit the tag it creates. I'm not entirely certain what happens if you simply create the *LOF tag manually, but I suspect Frame won't like it (and it sounds like it doesn't).
It sounds like you are almost but not quite doing the process for creating a generated file correctly, and it might be easier for you to delete the LOF file and start from scratch.
1. Open the book file for the document you are generating an LOF for.
2. Select the chapter file that will come AFTER the LOF.
3. Click Insert > List of > Figures
4. In the Set Up List of Figures window, select all the tags for the figures you want to include in the LOF.
5. Click OK.
6. Select the book file and click Edit > Update Book. This regenerates the generated files.
7. Open the *LOF file.
8. View the reference pages (View > Reference).
9. Find the reference page labeled LOF.
10. Put your cursor in one of the lines that controls the information included in your LOF.

11. Open the paragraph designer and edit the settings, then click Update Style.
12. Go back to the body page (View > Body) and regenerate the book.
This should result in a fresh LOF with the correct formatting.
By the way, I suggest you invest in something like the Tech Comm Tools book, FRAMEMAKER: Working with Content, by Matt Sullivan. It's an excellent reference and will walk you through pretty much anything you need to know how to do in Frame.