Question splitter issue

[356g3]

I got an Amazon basic hdmi splitter.Common one but its name is in Chinese only. Anyway it works as a 2 to 1 and was advertised as a passive but it does have a micro usb power in and I find it wont work without power in..
So much for passive.But it works.Maybe you cant use more than a 1 ft hdmi cord...anyway...
Here is the issue..I used a USB C male to USB A female adaptor to power it from a thunderbolt port...(they give you a cord)...but it didn't work.. I checked the thunderbolt port and its good...new Mac M1...but the splitter does work when you use regular USB A port...why might it be that way???

 

[COLGeek]

Can you post a link of the exact device you are referring to? This will allow others to determine what we are dealing with and how it works (or doesn't).