I also bought TP-LINK NG421 2.5G(RTL8125B) and encountered the same problem as you but I'm using v1.03b DS3617XS. Dose anyone has newer extra.lzma that works?
Thanks for your helps
- DSM version prior update: DSM 6.2.3-25426
- Loader version and model: Jun's Loader v1.03b DS3617XS
- Using custom extra.lzma: extra3617_v0.11_test