Latest Facebook Messenger 231 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; Android 9; vivo 1818 Build/PKQ1.190302.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/83.0.4103.106 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 9 V15 Pro
Mozilla/5.0 (Linux; Android 9; MRD-LX1F Build/HUAWEIMRD-LX1F; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/76.0.3809.132 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 9 Y6 (2019)
Mozilla/5.0 (Linux; Android 9; INE-LX2 Build/HUAWEIINE-LX2; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.162 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 9 Nova 3i
Mozilla/5.0 (Linux; Android 7.0; V2_Viper_S Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/69.0.3497.100 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 7 V2 Viper S
Mozilla/5.0 (Linux; Android 7.0; V2_Viper_S Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/68.0.3440.91 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 7 V2 Viper S
Mozilla/5.0 (Linux; Android 7.0; SM-J730G Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/58.0.3029.83 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 7 Galaxy J7 Pro
Mozilla/5.0 (Linux; Android 7.0; LGMS210 Build/NRD90U; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/58.0.3029.83 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 7 Aristo
Mozilla/5.0 (Linux; Android 6.0.1; Redmi Note 3 Build/MMB29M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.157 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 6 Redmi Note 3
Mozilla/5.0 (Linux; Android 5.1; vivo 1707 Build/LMY47I; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/50.0.2661.86 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 5 Y51 (2015)
Mozilla/5.0 (Linux; Android 5.1.1; SM-J105Y Build/LMY47V; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/55.0.2883.91 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/231.0.0.25.121;] Android 5 Galaxy J1 Mini