Netflix has added the Asus ZenFone 6, ROG Phone II as well as the TCL 10L and 10 Pro to its list of HD-compatible devices list. In addition, the ROG Phone II and TCL 10 series phones have gained HDR-10 playback compatibility. In order to view HD and HDR content on streaming apps your phone, you need Widewine L1 certification but even some devices with this certification are not eligible if the streaming platform doesn't explicitly whitelist them as was the case here. Thus it seems Netflix and other video streaming apps have their own criteria for whitelisting phones so its...
Source: https://www.gsmarena.com/asus_zenfone_6_rog_phone_ii_and_tcl_10_series_gain_netflix_hd_certification_-news-43586.php