hi there, wondering if I could get some help here:
I have an old CRT tv black and white, I’ve plugged it to an HDMI/composite to RF modulator HDM69

It used to work some time ago but can’t find out why it doesn’t anymore

When I don’t plug anything it seems alright (but not sure it really is) but as soon as I plus HDMI or composite my tv doesn’t display things right
Notice that it works on my modern tv
Here is a video showing what’s happening

Any ideas ? <3

PS: the horrible noise is my vaccum cleaner