But numerous tensions emerged within the group, including by the French state increasing its stake in Renault in 2015 and the 2018 arrest of its leader Carlos Ghosn in Japan on suspicion of financial misconduct and his subsequent flight from the country.

Source: https://www.citizen.co.za/motoring/renault-cuts-stake-in-nissan-further-as-means-of-impriving-alliance/

The Renault-Nissan alliance, which also includes junior partner Mitsubishi Motors Corp, was deeply strained by the 2018 ouster of its architect and former chairman, Carlos Ghosn, amid financial scandal.

Source: https://financialpost.com/pmn/business-pmn/renault-cedes-power-at-nissan-for-uncertain-benefits