[ThreePuttinDude]

I was issued a patent 6 years ago, and was warned in a very forceful
manner to keep my mouth shut and not jump at foreign offers for my product.

International patents trump US patents, I was told.

[BuffaloJack]

“International patents trump US patents”.
Not true. A patent’s protection is only good in the country issued. If, however, someone from another country copies your invention, they call sell it anywhere you don’t have a patent. If they try and bring it here, you get an attorney and take them to court, because that is infringement.

I currently hold about 20 US patents and about 45 foreign patents covering the same inventions as the 20 US patents. Any intellectual property lawyer will tell you that a patent is only as good as your will to sue for infringement.