I had an issue where one keyboard (worked with another one) worked in bootloader, but not when entering the encryption password after that. I believe I solved that by moving keyboard earlier in the module list in mkinitcpio.conf. Maybe something similar would solve your issue?
I have never ordered something from Amazon. It was introduced in my country a few years back, but it isn’t really that good of a site (at least the few times I have visited it).
Like many here, I do not want to support a monopolistic company like Amazon. Luckily I live in a country where I have better options. I tend to buy things from plenty of well rated sites. Environmentally conscious sites if I can.
I could see myself buying from them if there genuinely isn’t another option and it is something I really need, but that has yet to happen.