eclipse,
So you currently reside in the US and are a US citizen who previously resided in Canada with Landed Immigrant status. When last visiting Canada they, for the first time, insisted you relinquish your Landed Immigrant status – presumably because you haven’t resided in Canada for a while. Somehow you managed to get around that problem last time, but are concerned you will have the same problem next time you attempt to visit Canada, thus you haven’t visited Canada in a while, and wish to get your Canadian status resolved in a positive manner.
If I understand your situation correctly, you will be needing a Canadian lawyer, not an American one.