Does not making the exact same behavior in one Android API version look too unprofessional?

I've problems with implementing a certain behavior in an app I'm creating, exactly when this app is run with Android API 28 (the last one by the moment). Being able to implement it nicely in all the previous versions that my app support. It seems that it's something pretty hard to implement in this version, as I've been researching for hours with no advance.

Point is I could almost maintain all the mentioned behavior in that API with a simple change. This change would make for a slightly worse user experience, but nothing too troublesome.

If I decide to do that I'm then wondering which might be the best action among the two possibilities that open:

1) Maintain the whole behavior in all previous APIs, but change it in API 28 (and posterior ones). So, although users with API 28 (and likely the next ones) get a slightly worse user experience in that, the rest can get the improved version).

2) Make all previous versions stick to the same behavior I would change API 28 with, as maybe it would look too unprofessional that in this API (and likely posterior ones, if I'm not able to grasp how the problem would be solved) I'm not able to implement that certain behavior.

Which would be the best way to follow with the condition that I finally make that change?