What is the ruling on saying "O Allah, do not try us except with Your obedience," intending the trial of love?

Firstly, one should adhere to the prescribed supplications (du'as). The door of du'a is wide, but it has its Shariah-compliant controls. The du'a mentioned in the question is problematic because discord (fitna) is blameworthy, seeking refuge from it is legislated, and asking for it contradicts what has been ورد شرعًا (revealed in religious texts). Therefore, supplicating with it is not advisable. It is preferable to ask Allah for well-being from tribulations.