Help! My new Huawei BE3 (WiFi 7) has less range and speed than my old Steren router through walls.

​Hi everyone! I recently upgraded to a Huawei BE3 (WiFi 7) router, but I'm disappointed with its power and range. ​It’s connected via Ethernet to my main modem. The signal drops drastically when crossing just one wall, and even in the same room, I'm getting about 10 Mbps less than with my previous router, a Steren COM-870 (AC1200).

​I wanted to upgrade for better performance, but currently, the old "budget" router is outperforming the new one. ​Does anyone have tips on the best configuration for this specific Huawei model or how to improve signal penetration for a two-story house? I would really appreciate your help!