My daily's an Acer Aspire 5, very similar original specs to this: https://www.productindetail.com/pn/xvw-acer-aspire-5-a515-51g-55xl-2#specs, although it's an A515-51G-515J, not a ...55xl & I've maxed out the RAM(20GB), replaced the screen w/ a 120hz IPS display, & mine came w/ an SSD in place of the spinning HDD(I bought it on ebay a couple years ago). It boots from a fast 1TB NVMe 'drive'.
I've been using it nearly every day at work since getting it 1.5-2 years ago &, just in the last week, I've noticed that it doesn't stay in sleep mode like it used to. It's not waking up as far as I can tell because when I boot it up later, its battery's mostly 'full'. I put it to sleep toward the end of my ~12hr work shift & about 12-14 hrs later will set it up again at work, but find that it's completely shut down. This wasn't a problem until sometime in the last week. I've made no hardware changes to it for months now(the last one being a replacement of the display cable that had some loose connections or something causing the screen to flicker when adjusting its angle, & later for no apparent reason) & no new software, except perhaps Windows updating. I know many have had issues with Windows doing something while the system's supposed to be sleeping & it makes the laptop hot & kills the battery. I'm not noticing it getting hot, nor sucking battery charge, as mentioned above, but it won't stay in sleep mode like it used to. Any ideas?