Through learning, policy actors can maintain, reinforce, or revise their beliefs and positions about the design and outcomes of policies. This paper critically analyzes factors influencing policy learning by comparing policy processes of two EU laws of the recent "Fit for 55" climate package: (i) revised provisions on increasing energy efficiency in companies included in the recast Energy Efficiency Directive and (ii) the new FuelEU Maritime regulation provided for decarbonizing maritime shipping. Learning across coalitions with competing beliefs was encountered in the first case but not in the other despite similar institutional settings. The difference is attributed to a more politicized debate on decarbonizing shipping, leading to consensus through bargaining instead of deliberation, and a circumscribed leader of one coalition, with a less flexible negotiation mandate. The paper adds to the theory on policy learning, suggesting that levels of politicization and polarization, as well as the mandates of the coalition leaders, influence cross-coalition learning.