That's right it's just Santin
https://www.handsetdetection.com/device-detection-database/devices/santin/bitbiz-v58/

Also, I still have a list of useragents

• Mozilla/5.0 (Linux; Android 6.0; SANTIN GreenOrange Build/MRA58K; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/44.0.2403.119 Mobile Safari/537.36

• Mozilla/5.0 (Linux; Android 6.0; SANTIN halove) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.93 Mobile Safari/537.36

• Mozilla/5.0 (Linux; Android 6.0; SANTIN JS) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.157 Mobile Safari/537.36

• Mozilla/5.0 (Linux; Android 6.0; SANTIN monica) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.143 Mobile Safari/537.36

• Mozilla/5.0 (Linux; Android 6.0; SANTIN POWER Build/MRA58K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.89 Mobile Safari/537.36

• Mozilla/5.0 (Linux; Android 6.0; SANTIN S6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Mobile Safari/537.36

• Mozilla/5.0 (Linux; Android 6.0; SANTIN V9 Build/MRA58K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Mobile Safari/537.36 OPT/2.1

• Mozilla/5.0 (Linux; Android 6.0; SANTIN YSL-Y7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.116 Mobile Safari/537.36