How a device recovers from a standby will vary from one chipset to the other. Because of that I never even bother with standby. Just way too annoying with many devices (not just buzz). Hell, even laptops crap out their wifi connections after standby or hibernates. 90% of my devices are now hardwired (does not make them immune to network issues - but it is better). But the one thing I decided many years ago, is that media boxes are just not worth putting in standby mode. Take all of 45 seconds to boot them clean from scratch, and when it is a clean boot, they typically always initialize properly. Instantaneous gratification of the box turning on instantly, just to find out some hardware stayed asleep, is just not worth it.
Why not change the powerkey definition from standby to shutdown (which in my opinion should be the default) and save yourself all the headaches for now. If it can be fixed, I am sure Buzz will eventually look at it.
If you want to debug/test it any further, then obviously a pin hole hardware type factory reset should be the first thing to do to ensure there is nothing latched somewhere during some previous update.