。
May I ask you one more time?
Literal
One-more-time ask-[humble-伺って] good [question-ですか].
伺う (うかがう) is the humble/polite form of 聞く ('to ask') and 訪ねる ('to visit'). もう一度伺ってよろしいですか is a maximally polite request to repeat something — よろしい is the formal form of いい. This is keigo in action: the speaker humbles their own action (伺う) while elevating the permission framework (よろしい).