There is basically no difference between these two words. The dictionary Duden says that 'gerne' is rather used in Southern Germany (https://www.duden.de/rechtschreibung/gern) and in dictionaries there are just listed as synonyms (https://dict.leo.org/englisch-deutsch/gerne). According to my experience (I am from Austria) people rather use 'gern' and this is confirmed by the following article from Germany: The form with the ending-e is the older one. As with many other words, the ending syllable has been left out over time in the spoken language. Since language is in a constant, never-ending optimization process, end syllables that do not have a grammatical function will sooner or later be rejected. So nowadays you hear "gern" more often than "gerne". (https://www.spiegel.de/kultur/zwiebelfisch/zwiebelfisch-abc-gerne-gern-a-323744.html)

thank you so much for your encouragement, Felix.

Hi U U, I totally understand the frustration. When learning german it seems like there is a special rule for everything. But even in our technical language we tend to get "lazy" and cut corners. This would be such an example. Keep it up with the good questions! -Felix