I just got off the phone with Chamberlain Tech Support, having spent around 75 minutes between being on hold and being assisted. I have no complaints about the quality of the service, although I am highly frustrated with the result. I've tried posting, replying to similar posts, and emailing Chamberlain several times over the past few weeks and I have gotten no reply - as I see others have had similar issues.
Tech support told me that Genie Openers Made in 2016 or later are not compatible with and cannot be controlled by MyQ Garage. It's not clear to me if it is all Genie models or just some, but mine is a Gene 3024 manufactured in 2016. Checking the compatibility chart today, for Genie it says "all garage door openers manufactured after 1996 (Intellicode 1 and Intellicode 2)." I could find no reference to any models not working, and despite several posts from others about problems with certain Genie openers, no replies from Chamberlain about this. They told me they would update the compatibility chart online, but since it isn't there now, I felt it vital to post as quickly as possible to help out others.
If you're in the return window and having a similar issue you may want to think about doing so before you window expires Chamberlain told me that they could not take the product back directly if I'm not able to return it to where I bought it from. Otherwise, I recommend calling Chamberlain support and asking what they can do, but from my experience so far, it doesn't appear there's much besides encouraging me to take it back to where I got it from. I offered to return the product directly to them along with a sales receipt showing how much I paid for it, but they refused.