Latest Facebook Messenger 240 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; Android 9; ZTE Blade V10 Vita Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/78.0.3904.90 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/240.1.0.16.120;] Android 9 Blade V10 Vita
Mozilla/5.0 (Linux; Android 9; SH-04L Build/S7312; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/78.0.3904.96 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/240.1.0.16.120;] Android 9 Aquos R3
Mozilla/5.0 (Linux; Android 9; POT-LX3 Build/HUAWEIPOT-L03; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.136 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/240.1.0.16.120;] Android 9 P smart (2019)
Mozilla/5.0 (Linux; Android 9; ANE-LX1 Build/HUAWEIANE-L0101; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/78.0.3904.108 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/240.1.0.16.120;] Android 9 P20 Lite
Mozilla/5.0 (Linux; Android 8.0.0; WAS-LX1 Build/HUAWEIWAS-LX1; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/72.0.3626.105 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/240.1.0.16.120;] Android 8 P10 Lite