I don't now what exactly the sleep bug is, but all of my Macs for the last 15 years have had issues waking from sleep when plugged into an external monitor. My M1 Pro MBP had it. So did my 2018 MBP. My 2016 MBP had it really bad, but the worst offender was my 2012 MBP.
I've occasionally had some issues with my devices waking from sleep even without the external monitor. At least in some cases, it's safe to say it's a software issue that's independent of the hardware. There has to be something deep in MacOS regulating sleep that is always barely working as intended because nearly every time Apple releases a new OS version, I know there's a good chance sleep issues will return. I've come to expect that so much that I try to wait 6-12 months before updating OS versions. That's usually how long it takes Apple to re-fix that constantly recurring bug again.
If it's not happening to you, I wouldn't worry about it and if it is happening, my experience as someone who's experienced the whole gamut of laptop sleep issues is that it's mostly just an annoyance. It scares you the first few times it happens, but you quickly learn how to recognize that it's not broken. It just needs a reboot.
I've occasionally had some issues with my devices waking from sleep even without the external monitor. At least in some cases, it's safe to say it's a software issue that's independent of the hardware. There has to be something deep in MacOS regulating sleep that is always barely working as intended because nearly every time Apple releases a new OS version, I know there's a good chance sleep issues will return. I've come to expect that so much that I try to wait 6-12 months before updating OS versions. That's usually how long it takes Apple to re-fix that constantly recurring bug again.
If it's not happening to you, I wouldn't worry about it and if it is happening, my experience as someone who's experienced the whole gamut of laptop sleep issues is that it's mostly just an annoyance. It scares you the first few times it happens, but you quickly learn how to recognize that it's not broken. It just needs a reboot.