There is a kind of "good neighbour" protocol as part of the Wi-Fi standards that mean any nearby Wi-Fi devices that are transmitting above a certain signal level have to "play nice together." I'll spare the details of how this works, but the threshold signal level at which a wannabe transmitter has to "wait" for for some "clear air" are lower for Wi-Fi neighbours that cannot hear each than for those that can.
Typically in the 2.4GHz waveband, Wi-Fi sources choose a channel plan based on [1,6,11] (sometimes, though rarely, [1,5,9,13].) Neighbouring devices aligned on the same channel plan can "hear" and decode each others transmissions, and the "good neighbour" protocol kicks in.
Changing your AP to a "non-aligned" channel means that it (and respectively your neighbours) cannot decode neighbouring transmissions and will regards them as "noise" or some non-Wi-Fi source - Wi-Fi is not the only thing that uses these radio frequencies. The "rules" about transmitting mean that Wi-Fi devices are more conservative about avoiding non-Wi-Fi sources (won't stomp over them) than for Wi-Fi sources, so by tuning to a "non-aligned" (with the neighbours) radio channel, you could actually make things worse not better.
As Captain Morgan indicates, you could try a different (1,6,11 aligned) channel, but it tends to be a bit of a hiding to nothing as so many people leave their routers/AP's "auto-tuning" that it's only a matter of time before it all flips round again and you're back to square one.
I live in flats and way back when, I could find a 2.4GHz more or less to myself, but a couple of decades later and everyone has Wi-Fi there's just no chance of it. I suffer the same issue that every so often, some of my Wi-Fi clients (particularly my laptop) just falls off the network. In an ideal world, I'd use 5GHz where signal propagation is lower so co-channel interference is less of an issue, and there's more channels available, but my particular laptop's is 2.4GHz only so just have to live with it.
BTW - with an "infrastructure" Wi-Fi system (one with routers/AP's rather than a "closed "ad-hoc" system) you shouldn't need you HP printer to advertise itself as a Wi-Fi device (essentially it's functioning as an AP, probably to facilitate some form of "direct print" or similar feature.) Consult the printers manual and "just" configure it as a regular Wi-Fi client connected to your router/AP like any other and it will stop advertising itself. That's then one source of interference removed. Better still, if it is possible to connect the printer with a wired ethernet cable, do that and turn off printer's Wi-Fi functionality entirely (though some printers don't have ethernet and are Wi-FI only, so you're stuck with it.)