that often means that amazon servers are having a bad day - all you can do is watch netflix for a while instead, - and if netflix is good that proves that your device, your hub, your wifi... is all good.
no point calling amazon , they will blame your ISP, your app,.. anything but their servers....
thankfully it is a rate event - for me anyway.
if you are on one of their cheap fire sticks or boxes then a reboot of the fire device might fix it, those things seem to need regular reboots to keep them workign well . but more often it is bad for an evening on all your amazon video enabled devices, proving its not a device issue
you can also check the various is it down sites, e.g.