The apple apologists here are so funny... while others like me are more willing to solve and discover issues FOR Apple. Cheerleading the brand and "it's good as it is, take it or leave it" is not going to make the issues disappear.
So I also have the problem with waking up my external monitors on my M1 Mac Mini. Originally, it was the LG monitor connected to the HDMI port. I suspect this is maybe fixable through hardware, so I went to purchase a HDMI 2.0 cable as I was using a HDMI 1.4 cable, and viola! The monitor is good now...
BUT!!! BUT!! My the other monitor connected to USB-c (also LG) starts to experience this wake-up issue after I changed the cable for my previously mentioned monitor. It had no issue before.
So, my uneducated guess tells me, the M1 Mac Mini has some sort of bandwidth limitation issue (!?) and that results in monitors (if more than 1) not getting the proper information from the computer.
Therefore, if there's no software update for this, the only way in my eyes that this is somehow fixable, is to play around with different ports using different cables and hubs and adapters. Maybe it will be working then.
(no bluetooth issue on my part, only no instant connection when I turn on the mac)