Latest Facebook Messenger 119 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; U; Android 4.3; en-us; ZTE-Z669 Build/JLS36C) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 4 Z669
Mozilla/5.0 (Linux; Android 7.0; VTR-L09 Build/HUAWEIVTR-L09; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/61.0.3163.98 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 7 P10
Mozilla/5.0 (Linux; Android 7.0; MI 5 Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/64.0.3282.137 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 7 Mi 5
Mozilla/5.0 (Linux; Android 6.0; ALE-L21 Build/HuaweiALE-L21; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/61.0.3163.98 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 6 P8 Lite (2015)
Mozilla/5.0 (Linux; Android 6.0.1; P01T_1 Build/MMB29P; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/51.0.2704.81 Safari/537.36 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 6 ZenPad 10
Mozilla/5.0 (Linux; Android 5.1.1; HUAWEI SCL-L21 Build/HuaweiSCL-L21) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/39.0.0.0 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 5 Y6
Mozilla/5.0 (Linux; Android 4.4.2; SM-G7102 Build/KOT49H) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/30.0.0.0 Mobile Safari/537.36 [FB_IAB/MESSENGER;FBAV/119.0.0.18.91;] Android 4 Galaxy Grand 2