I got Linux earlier this year (still kinda a Linux noob too, so sorry in advance, I might be slow to understand stuff) and ever since I got Linux, this has been a reoccurring issue. When I would come back to my PC being asleep, I would tap my keyboard to wake it back up. Keyboard lights up, I hear the PC's fans working, and I hear the volume sound effect when I turn it up. If I try tapping the power button, it shuts the whole thing off and I have to turn my PC back on, then everything returns to normal.
I've been sitting on this issue the whole time, but I finally looked into it and researched the issue myself. While I learned it's fairly common apparently, I still can't get why I'm having the issue. and could really use some help. I don't have a NVIDIA graphic card, I use AMD. I updated my kernel a few times since then so I'm not sure if it has anything to do with kernel's either.
LMDE 7 - Cinnamon 64-bit.
One other thing, from the day I got Linux, I've always been met with this error on boot. Looked into it, it doesn't seem harmful but I will mention it in case it's related. (I copied this from the mint Linux forums I had bookmarked, so I don't remember if I had the exact numbers or anything)
ACPI Bios error (bug): could not resolve symbol [\SB.PC00.TXHC.RUB.ss01], AE_NOT_FOUND (20210730/dswload2-162)
ACPI Error: AE-NOT_FOUND, During name lookup/catalog (20210730/psobject-220)