The above mentioned tradition has been transmitted through a different chain of narrators by 'Ubadah b. al-samit like the version of al-Rabi’b Sulaiman. This version adds: Makhul used to recite Surah al Fatihah al-kitab quietly in the prayer in which the imam recites the Qur’an loudly when he observes the period of silence. If he does not observe the period of silence, recite it before him(i.e before his recitation), or along with him or after him; do not give it up in any case.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَلِيُّ بْنُ سَهْلٍ الرَّمْلِيُّ، حَدَّثَنَا الْوَلِيدُ، عَنِ ابْنِ جَابِرٍ، وَسَعِيدِ بْنِ عَبْدِ الْعَزِيزِ، وَعَبْدِ اللَّهِ بْنِ الْعَلاَءِ، عَنْ مَكْحُولٍ، عَنْ عُبَادَةَ، نَحْوَ حَدِيثِ الرَّبِيعِ بْنِ سُلَيْمَانَ قَالُوا فَكَانَ مَكْحُولٌ يَقْرَأُ فِي الْمَغْرِبِ وَالْعِشَاءِ وَالصُّبْحِ بِفَاتِحَةِ الْكِتَابِ فِي كُلِّ رَكْعَةٍ سِرًّا . قَالَ مَكْحُولٌ اقْرَأْ بِهَا فِيمَا جَهَرَ بِهِ الإِمَامُ إِذَا قَرَأَ بِفَاتِحَةِ الْكِتَابِ وَسَكَتَ سِرًّا فَإِنْ لَمْ يَسْكُتِ اقْرَأْ بِهَا قَبْلَهُ وَمَعَهُ وَبَعْدَهُ لاَ تَتْرُكْهَا عَلَى حَالٍ .
sunnah.com