Hey guys, I had the same issue, but I think I figured it out. And I’m pretty sure it is an App bug.
When on the page for setting the 2.4ghz password, click the “eyeball” to “show password”. Then click next. This worked 100% of the time for me, after spending 45 minutes setting up the first bulb.
After this I tested multiple scenarios on 3 more bulbs and in every case selecting the “show password” button made it work
One lat note: When using Android, it’ll earn you if you connect to a network with not internet. Make sure you click the pop-up and select “Stay connected” or sometimes it’ll block the connection, assuming it to be unsafe.