"Is" is correct and not "Are", as "problem" refers to "Jack Eichel" and not "Golden Knights". If you reverse the sentence it is clear: "Jack Eichel is the Golden Knights problem".
The main issue is that the title is missing an apostrophe after "Knights" to mark it as a possessive. It should be "Golden Knights' problem".
However I hope they don't fix it as the thread title is so close to being right but fails by just the smallest margin, which is so fitting considering the topic of this thread
It's almost as if the OP jinxed Vegas from the start of this thread with that missing apostrophe!