Latest Facebook 321 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/91.0.4472.88 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Blade V10 Vita
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/90.0.4430.210 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Blade V10 Vita
Mozilla/5.0 (Linux; Android 9; ZTE Blade A5 2020 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.88 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Blade A5 (2020)
Mozilla/5.0 (Linux; Android 9; ZTE Blade A5 2020 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/90.0.4430.210 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Blade A5 (2020)
Mozilla/5.0 (Linux; Android 9; XT1514 Build/PQ3A.190605.003; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.157 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Moto E
Mozilla/5.0 (Linux; Android 9; W-V800-EEA Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/92.0.4515.159 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 View 3 Lite
Mozilla/5.0 (Linux; Android 9; W-V720-EEA Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.77 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y80
Mozilla/5.0 (Linux; Android 9; W-V720-EEA Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/90.0.4430.210 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y80
Mozilla/5.0 (Linux; Android 9; W-K510-EEA Build/PPR1.181008.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.88 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y60
Mozilla/5.0 (Linux; Android 9; VTR-L09 Build/HUAWEIVTR-L0901; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.88 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 P10
Mozilla/5.0 (Linux; Android 9; VTR-L09 Build/HUAWEIVTR-L0901; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.101 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 P10
Mozilla/5.0 (Linux; Android 9; VTR-L09 Build/HUAWEIVTR-L0901; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/90.0.4430.210 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 P10
Mozilla/5.0 (Linux; Android 9; vivo Z1 Build/PKQ1.180819.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/68.0.3440.91 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Z1
Mozilla/5.0 (Linux; Android 9; V1934A Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/68.0.3440.91 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y5s
Mozilla/5.0 (Linux; Android 9; V1930A Build/PKQ1.190616.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/94.0.4606.71 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y3 Standard
Mozilla/5.0 (Linux; Android 9; V1913T Build/P00610; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/116.0.0.0 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y7s
Mozilla/5.0 (Linux; Android 9; V1913T Build/P00610; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/114.0.5735.227 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Y7s
Mozilla/5.0 (Linux; Android 9; TECNO KC1 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/90.0.4430.91 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Spark Air
Mozilla/5.0 (Linux; Android 9; STF-L09S Build/HUAWEISTF-L09S; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.88 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Honor 9
Mozilla/5.0 (Linux; Android 9; SNE-LX1 Build/HUAWEISNE-L01; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/90.0.4430.210 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/321.0.0.37.119;] Android 9 Mate 20 Lite