9m is going to be tough... You're right at the limit and I'd go active cables.
I've only ever dealt with long HDMIs in a commercial setting where a dodgy cable can cost hundreds to thousands so I can't recommend any 'cheap' cables. I've just looked and I do see a recommendation for PureLink Ultimate Series cables although can't think if I've ever used them. Worth a go?
I like CYP HDMI switches...
e; like this
EL-41S-4K22
I'm going to assume (wrongly hopefully) that spending close to £400 wasn't your plan