Is this a Tango burnout, or more of a Tango fall off? Either way you see it, it is something that not only is effecting you, but others as well in your community. So what can you do? If you don’t want to feel discouraged and you love Tango, you might need to bring friends or others into the dance to fill the gap. This might sound appealing, or the thought might push you away, but it something you can do to help fill those voids that others who leave. This will help only for this situation, but what about others? Lack of class challenges, few at your skill level to dance or practice with, other dancers who you aren’t comfortable dancing with, or a few others also come to mind.
If classes aren’t fulfilling what you feel you need, you can chat with the teachers, most will take your suggestions to heart and might refer you to another teacher who could help, or add things or focus on things more in a class or few. Teachers want to help you, and want input from their community on what could be better. Maybe a private lesson every once in a while could help. This almost starts to get to the territory of not having someone at a similar skill level to practice or work with, which is a matter on just asking, or finding someone, or bringing someone in. You will have to be pro-active if you need/want someone to help, and don’t be afraid to ask those that are more experienced dancers, they might have the same problem and happy to work with you and then you both can start improving once things level out between you two.