I think we are talking about 2 words with different meaning and pronunciation. Stingy - unwilling to share is pronounced with ‘ j’ in British and American English. Stingy derived from a sting / stinger ( a part of an insect that stings you) is pronounced with hard ‘ g’. It means able to sting, stinging. Stinging is more frequently used , a stinging insect or pain. But you can still see ‘stingy’ being used. I hope it clarifies the confusion :)

The g in stingy is pronounced the same as the first sound in January and the two sounds in judge. I have never heard a hard g like get or Gaga. The dictionaries that I checked are all the same. Which online dictionary had that hard g?

It is the first option. To the best of my knowledge, it is pronounced the same in most varieties of English.

It is "stin-jee".

It is as a j. You may get a problem with machine pronouncing it with a g, but it is a j.