Multiadapter is not charging MacBook Air with the same power as usual

Since I have the multiadapter (USB-C, HDMI and USB-A) I've been charging the MacBook air (2020 m1) from its USB-C port without any problem. I do this because cable management and because it leaves a free built in port to connect my iPad used as a second monitor with sidecar that does not work connected via multiadapter.

The problem is that is not charging the MacBook with the same power, meaning that while it is connected and it recognize that is charging, the level of the battery is still decreasing.

Why? and How to fix it?

Thanks!