Bubbles won't turn golden
I have been trying to strengthen some of my bubbles. I even did the test out and while it says I am at full strength, the bubble does not turn gold.
I don't have a mobile so use my laptop to do Duolingo. From all the comments I've read, it sounds like the desktop/laptop version has fewer problems than the mobile version - possibly due to more testing of new features being done on the mobile version. I hope you resolve your problem.