which magisk module did you use?If it helps I got back the widevine L1 by installing the latest beta (21.6.2).
Netflix is recognized with L1 certificate while Prime Video remains in SD quality, so I tried using a magisk module to change the model name to Mi 10 and I got HDR10 on Netflix and maximum quality (2,35GB/h) on Prime Video.
=> https://xiaomi.eu/community/threads/info-widevine-l1-support.61064/Hello, can you share the zip to install from magisk. I don't use telegram
Really need widevine L1.